Sidelink Scheduling Request in a Wireless Network

ABSTRACT

A wireless device transmits, one or more radio resource control (RRC) messages indicating assistance information for a sidelink operation. The assistance information indicates: an identifier indicating a logical channel associated with a sidelink traffic; and one or more periodicities associated with the logical channel. In response to the assistance information, one or more second RRC messages indicating one or more configured grant configurations determined based on the one or more of periodicities of the logical channel is received. The wireless device triggers, a transmission of a buffer status report in response to sidelink data of the logical channel becoming available. A scheduling request (SR) is transmitted. In response to the SR: the transmission of the buffer status report is cancelled; and one or more activation commands indicating activation of the one or more configured grant configurations is received.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/932,084, filed Nov. 7, 2019, which is hereby incorporated byreference in its entirety.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of several of the various embodiments of the present disclosureare described herein with reference to the drawings.

FIG. 1A and FIG. 1B illustrate example mobile communication networks inwhich embodiments of the present disclosure may be implemented.

FIG. 2A and FIG. 2B respectively illustrate a New Radio (NR) user planeand control plane protocol stack.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack of FIG. 2A.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack of FIG. 2A.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.

FIG. 5A and FIG. 5B respectively illustrate a mapping between logicalchannels, transport channels, and physical channels for the downlink anduplink.

FIG. 6 is an example diagram showing RRC state transitions of a UE.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier.

FIG. 10A illustrates three carrier aggregation configurations with twocomponent carriers.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups.

FIG. 11A illustrates an example of an SS/PBCH block structure andlocation.

FIG. 11B illustrates an example of CSI-RSs that are mapped in the timeand frequency domains.

FIG. 12A and FIG. 12B respectively illustrate examples of three downlinkand uplink beam management procedures.

FIG. 13A, FIG. 13B, and FIG. 13C respectively illustrate a four-stepcontention-based random access procedure, a two-step contention-freerandom access procedure, and another two-step random access procedure.

FIG. 14A illustrates an example of CORESET configurations for abandwidth part.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing.

FIG. 15 illustrates an example of a wireless device in communicationwith a base station.

FIG. 16A, FIG. 16B, FIG. 16C, and FIG. 16D illustrate example structuresfor uplink and downlink transmission.

FIG. 17 illustrates an example of sidelink operation scenarios accordingto an aspect of an example embodiment of the present disclosure.

FIG. 18 illustrates an example of sidelink resource allocation accordingto an aspect of an example embodiment of the present disclosure.

FIG. 19 illustrates a normal BSR/SR procedure according to an aspect ofan example embodiment of the present disclosure.

FIG. 20 illustrates a normal BSR/SR procedure according to an aspect ofan example embodiment of the present disclosure.

FIG. 21 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 22 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 23 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 24 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 25 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 26 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 27 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 28 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 29 is an illustration of an aspect of an example embodiment of thepresent disclosure.

FIG. 30 is a flow diagram of an aspect of an example embodiment of thepresent disclosure.

DETAILED DESCRIPTION

In the present disclosure, various embodiments are presented as examplesof how the disclosed techniques may be implemented and/or how thedisclosed techniques may be practiced in environments and scenarios. Itwill be apparent to persons skilled in the relevant art that variouschanges in form and detail can be made therein without departing fromthe scope. In fact, after reading the description, it will be apparentto one skilled in the relevant art how to implement alternativeembodiments. The present embodiments should not be limited by any of thedescribed exemplary embodiments. The embodiments of the presentdisclosure will be described with reference to the accompanyingdrawings. Limitations, features, and/or elements from the disclosedexample embodiments may be combined to create further embodiments withinthe scope of the disclosure. Any figures which highlight thefunctionality and advantages, are presented for example purposes only.The disclosed architecture is sufficiently flexible and configurable,such that it may be utilized in ways other than that shown. For example,the actions listed in any flowchart may be re-ordered or only optionallyused in some embodiments.

Embodiments may be configured to operate as needed. The disclosedmechanism may be performed when certain criteria are met, for example,in a wireless device, a base station, a radio environment, a network, acombination of the above, and/or the like. Example criteria may bebased, at least in part, on for example, wireless device or network nodeconfigurations, traffic load, initial system set up, packet sizes,traffic characteristics, a combination of the above, and/or the like.When the one or more criteria are met, various example embodiments maybe applied. Therefore, it may be possible to implement exampleembodiments that selectively implement disclosed protocols.

A base station may communicate with a mix of wireless devices. Wirelessdevices and/or base stations may support multiple technologies, and/ormultiple releases of the same technology. Wireless devices may have somespecific capability(ies) depending on wireless device category and/orcapability(ies). When this disclosure refers to a base stationcommunicating with a plurality of wireless devices, this disclosure mayrefer to a subset of the total wireless devices in a coverage area. Thisdisclosure may refer to, for example, a plurality of wireless devices ofa given LTE or 5G release with a given capability and in a given sectorof the base station. The plurality of wireless devices in thisdisclosure may refer to a selected plurality of wireless devices, and/ora subset of total wireless devices in a coverage area which performaccording to disclosed methods, and/or the like. There may be aplurality of base stations or a plurality of wireless devices in acoverage area that may not comply with the disclosed methods, forexample, those wireless devices or base stations may perform based onolder releases of LTE or 5G technology.

In this disclosure, “a” and “an” and similar phrases are to beinterpreted as “at least one” and “one or more.” Similarly, any termthat ends with the suffix “(s)” is to be interpreted as “at least one”and “one or more.” In this disclosure, the term “may” is to beinterpreted as “may, for example.” In other words, the term “may” isindicative that the phrase following the term “may” is an example of oneof a multitude of suitable possibilities that may, or may not, beemployed by one or more of the various embodiments. The terms“comprises” and “consists of”, as used herein, enumerate one or morecomponents of the element being described. The term “comprises” isinterchangeable with “includes” and does not exclude unenumeratedcomponents from being included in the element being described. Bycontrast, “consists of” provides a complete enumeration of the one ormore components of the element being described. The term “based on”, asused herein, should be interpreted as “based at least in part on” ratherthan, for example, “based solely on”. The term “and/or” as used hereinrepresents any possible combination of enumerated elements. For example,“A, B, and/or C” may represent A; B; C; A and B; A and C; B and C; or A,B, and C.

If A and B are sets and every element of A is an element of B, A iscalled a subset of B. In this specification, only non-empty sets andsubsets are considered. For example, possible subsets of B={cell1,cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on”(or equally “based at least on”) is indicative that the phrase followingthe term “based on” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “in response to” (or equally “inresponse at least to”) is indicative that the phrase following thephrase “in response to” is an example of one of a multitude of suitablepossibilities that may, or may not, be employed to one or more of thevarious embodiments. The phrase “depending on” (or equally “depending atleast to”) is indicative that the phrase following the phrase “dependingon” is an example of one of a multitude of suitable possibilities thatmay, or may not, be employed to one or more of the various embodiments.The phrase “employing/using” (or equally “employing/using at least”) isindicative that the phrase following the phrase “employing/using” is anexample of one of a multitude of suitable possibilities that may, or maynot, be employed to one or more of the various embodiments.

The term configured may relate to the capacity of a device whether thedevice is in an operational or non-operational state. Configured mayrefer to specific settings in a device that effect the operationalcharacteristics of the device whether the device is in an operational ornon-operational state. In other words, the hardware, software, firmware,registers, memory values, and/or the like may be “configured” within adevice, whether the device is in an operational or nonoperational state,to provide the device with specific characteristics. Terms such as “acontrol message to cause in a device” may mean that a control messagehas parameters that may be used to configure specific characteristics ormay be used to implement certain actions in the device, whether thedevice is in an operational or non-operational state.

In this disclosure, parameters (or equally called, fields, orInformation elements: IEs) may comprise one or more information objects,and an information object may comprise one or more other objects. Forexample, if parameter (IE) N comprises parameter (IE) M, and parameter(IE) M comprises parameter (IE) K, and parameter (IE) K comprisesparameter (information element) J. Then, for example, N comprises K, andN comprises J. In an example embodiment, when one or more messagescomprise a plurality of parameters, it implies that a parameter in theplurality of parameters is in at least one of the one or more messages,but does not have to be in each of the one or more messages.

Many features presented are described as being optional through the useof “may” or the use of parentheses. For the sake of brevity andlegibility, the present disclosure does not explicitly recite each andevery permutation that may be obtained by choosing from the set ofoptional features. The present disclosure is to be interpreted asexplicitly disclosing all such permutations. For example, a systemdescribed as having three optional features may be embodied in sevenways, namely with just one of the three possible features, with any twoof the three possible features or with three of the three possiblefeatures.

Many of the elements described in the disclosed embodiments may beimplemented as modules. A module is defined here as an element thatperforms a defined function and has a defined interface to otherelements. The modules described in this disclosure may be implemented inhardware, software in combination with hardware, firmware, wetware (e.g.hardware with a biological element) or a combination thereof, which maybe behaviorally equivalent. For example, modules may be implemented as asoftware routine written in a computer language configured to beexecuted by a hardware machine (such as C, C++, Fortran, Java, Basic,Matlab or the like) or a modeling/simulation program such as Simulink,Stateflow, GNU Octave, or Lab VIEWMathScript. It may be possible toimplement modules using physical hardware that incorporates discrete orprogrammable analog, digital and/or quantum hardware. Examples ofprogrammable hardware comprise: computers, microcontrollers,microprocessors, application-specific integrated circuits (ASICs); fieldprogrammable gate arrays (FPGAs); and complex programmable logic devices(CPLDs). Computers, microcontrollers and microprocessors are programmedusing languages such as assembly, C, C++ or the like. FPGAs, ASICs andCPLDs are often programmed using hardware description languages (HDL)such as VHSIC hardware description language (VHDL) or Verilog thatconfigure connections between internal hardware modules with lesserfunctionality on a programmable device. The mentioned technologies areoften used in combination to achieve the result of a functional module.

FIG. 1A illustrates an example of a mobile communication network 100 inwhich embodiments of the present disclosure may be implemented. Themobile communication network 100 may be, for example, a public landmobile network (PLMN) run by a network operator. As illustrated in FIG.1A, the mobile communication network 100 includes a core network (CN)102, a radio access network (RAN) 104, and a wireless device 106.

The CN 102 may provide the wireless device 106 with an interface to oneor more data networks (DNs), such as public DNs (e.g., the Internet),private DNs, and/or intra-operator DNs. As part of the interfacefunctionality, the CN 102 may set up end-to-end connections between thewireless device 106 and the one or more DNs, authenticate the wirelessdevice 106, and provide charging functionality.

The RAN 104 may connect the CN 102 to the wireless device 106 throughradio communications over an air interface. As part of the radiocommunications, the RAN 104 may provide scheduling, radio resourcemanagement, and retransmission protocols. The communication directionfrom the RAN 104 to the wireless device 106 over the air interface isknown as the downlink and the communication direction from the wirelessdevice 106 to the RAN 104 over the air interface is known as the uplink.Downlink transmissions may be separated from uplink transmissions usingfrequency division duplexing (FDD), time-division duplexing (TDD),and/or some combination of the two duplexing techniques.

The term wireless device may be used throughout this disclosure to referto and encompass any mobile device or fixed (non-mobile) device forwhich wireless communication is needed or usable. For example, awireless device may be a telephone, smart phone, tablet, computer,laptop, sensor, meter, wearable device, Internet of Things (IoT) device,vehicle road side unit (RSU), relay node, automobile, and/or anycombination thereof. The term wireless device encompasses otherterminology, including user equipment (UE), user terminal (UT), accessterminal (AT), mobile station, handset, wireless transmit and receiveunit (WTRU), and/or wireless communication device.

The RAN 104 may include one or more base stations (not shown). The termbase station may be used throughout this disclosure to refer to andencompass a Node B (associated with UMTS and/or 3G standards), anEvolved Node B (eNB, associated with E-UTRA and/or 4G standards), aremote radio head (RRH), a baseband processing unit coupled to one ormore RRHs, a repeater node or relay node used to extend the coveragearea of a donor node, a Next Generation Evolved Node B (ng-eNB), aGeneration Node B (gNB, associated with NR and/or 5G standards), anaccess point (AP, associated with, for example, WiFi or any othersuitable wireless communication standard), and/or any combinationthereof. A base station may comprise at least one gNB Central Unit(gNB-CU) and at least one a gNB Distributed Unit (gNB-DU).

A base station included in the RAN 104 may include one or more sets ofantennas for communicating with the wireless device 106 over the airinterface. For example, one or more of the base stations may includethree sets of antennas to respectively control three cells (or sectors).The size of a cell may be determined by a range at which a receiver(e.g., a base station receiver) can successfully receive thetransmissions from a transmitter (e.g., a wireless device transmitter)operating in the cell. Together, the cells of the base stations mayprovide radio coverage to the wireless device 106 over a wide geographicarea to support wireless device mobility.

In addition to three-sector sites, other implementations of basestations are possible. For example, one or more of the base stations inthe RAN 104 may be implemented as a sectored site with more or less thanthree sectors. One or more of the base stations in the RAN 104 may beimplemented as an access point, as a baseband processing unit coupled toseveral remote radio heads (RRHs), and/or as a repeater or relay nodeused to extend the coverage area of a donor node. A baseband processingunit coupled to RRHs may be part of a centralized or cloud RANarchitecture, where the baseband processing unit may be eithercentralized in a pool of baseband processing units or virtualized. Arepeater node may amplify and rebroadcast a radio signal received from adonor node. A relay node may perform the same/similar functions as arepeater node but may decode the radio signal received from the donornode to remove noise before amplifying and rebroadcasting the radiosignal.

The RAN 104 may be deployed as a homogenous network of macrocell basestations that have similar antenna patterns and similar high-leveltransmit powers. The RAN 104 may be deployed as a heterogeneous network.In heterogeneous networks, small cell base stations may be used toprovide small coverage areas, for example, coverage areas that overlapwith the comparatively larger coverage areas provided by macrocell basestations. The small coverage areas may be provided in areas with highdata traffic (or so-called “hotspots”) or in areas with weak macrocellcoverage. Examples of small cell base stations include, in order ofdecreasing coverage area, microcell base stations, picocell basestations, and femtocell base stations or home base stations.

The Third-Generation Partnership Project (3GPP) was formed in 1998 toprovide global standardization of specifications for mobilecommunication networks similar to the mobile communication network 100in FIG. 1A. To date, 3GPP has produced specifications for threegenerations of mobile networks: a third generation (3G) network known asUniversal Mobile Telecommunications System (UMTS), a fourth generation(4G) network known as Long-Term Evolution (LTE), and a fifth generation(5G) network known as 5G System (5GS). Embodiments of the presentdisclosure are described with reference to the RAN of a 3GPP 5G network,referred to as next-generation RAN (NG-RAN). Embodiments may beapplicable to RANs of other mobile communication networks, such as theRAN 104 in FIG. 1A, the RANs of earlier 3G and 4G networks, and those offuture networks yet to be specified (e.g., a 3GPP 6G network). NG-RANimplements 5G radio access technology known as New Radio (NR) and may beprovisioned to implement 4G radio access technology or other radioaccess technologies, including non-3GPP radio access technologies.

FIG. 1B illustrates another example mobile communication network 150 inwhich embodiments of the present disclosure may be implemented. Mobilecommunication network 150 may be, for example, a PLMN run by a networkoperator. As illustrated in FIG. 1B, mobile communication network 150includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and156B (collectively UEs 156). These components may be implemented andoperate in the same or similar manner as corresponding componentsdescribed with respect to FIG. 1A.

The 5G-CN 152 provides the UEs 156 with an interface to one or more DNs,such as public DNs (e.g., the Internet), private DNs, and/orintra-operator DNs. As part of the interface functionality, the 5G-CN152 may set up end-to-end connections between the UEs 156 and the one ormore DNs, authenticate the UEs 156, and provide charging functionality.Compared to the CN of a 3GPP 4G network, the basis of the 5G-CN 152 maybe a service-based architecture. This means that the architecture of thenodes making up the 5G-CN 152 may be defined as network functions thatoffer services via interfaces to other network functions. The networkfunctions of the 5G-CN 152 may be implemented in several ways, includingas network elements on dedicated or shared hardware, as softwareinstances running on dedicated or shared hardware, or as virtualizedfunctions instantiated on a platform (e.g., a cloud-based platform).

As illustrated in FIG. 1B, the 5G-CN 152 includes an Access and MobilityManagement Function (AMF) 158A and a User Plane Function (UPF) 158B,which are shown as one component AMF/UPF 158 in FIG. 1B for ease ofillustration. The UPF 158B may serve as a gateway between the NG-RAN 154and the one or more DNs. The UPF 158B may perform functions such aspacket routing and forwarding, packet inspection and user plane policyrule enforcement, traffic usage reporting, uplink classification tosupport routing of traffic flows to the one or more DNs, quality ofservice (QoS) handling for the user plane (e.g., packet filtering,gating, uplink/downlink rate enforcement, and uplink trafficverification), downlink packet buffering, and downlink data notificationtriggering. The UPF 158B may serve as an anchor point forintra-/inter-Radio Access Technology (RAT) mobility, an externalprotocol (or packet) data unit (PDU) session point of interconnect tothe one or more DNs, and/or a branching point to support a multi-homedPDU session. The UEs 156 may be configured to receive services through aPDU session, which is a logical connection between a UE and a DN.

The AMF 158A may perform functions such as Non-Access Stratum (NAS)signaling termination, NAS signaling security, Access Stratum (AS)security control, inter-CN node signaling for mobility between 3GPPaccess networks, idle mode UE reachability (e.g., control and executionof paging retransmission), registration area management, intra-systemand inter-system mobility support, access authentication, accessauthorization including checking of roaming rights, mobility managementcontrol (subscription and policies), network slicing support, and/orsession management function (SMF) selection. NAS may refer to thefunctionality operating between a CN and a UE, and AS may refer to thefunctionality operating between the UE and a RAN.

The 5G-CN 152 may include one or more additional network functions thatare not shown in FIG. 1B for the sake of clarity. For example, the 5G-CN152 may include one or more of a Session Management Function (SMF), anNR Repository Function (NRF), a Policy Control Function (PCF), a NetworkExposure Function (NEF), a Unified Data Management (UDM), an ApplicationFunction (AF), and/or an Authentication Server Function (AUSF).

The NG-RAN 154 may connect the 5G-CN 152 to the UEs 156 through radiocommunications over the air interface. The NG-RAN 154 may include one ormore gNBs, illustrated as gNB 160A and gNB 160B (collectively gNBs 160)and/or one or more ng-eNBs, illustrated as ng-eNB 162A and ng-eNB 162B(collectively ng-eNBs 162). The gNBs 160 and ng-eNBs 162 may be moregenerically referred to as base stations. The gNBs 160 and ng-eNBs 162may include one or more sets of antennas for communicating with the UEs156 over an air interface. For example, one or more of the gNBs 160and/or one or more of the ng-eNB s 162 may include three sets ofantennas to respectively control three cells (or sectors). Together, thecells of the gNBs 160 and the ng-eNBs 162 may provide radio coverage tothe UEs 156 over a wide geographic area to support UE mobility.

As shown in FIG. 1B, the gNBs 160 and/or the ng-eNBs 162 may beconnected to the 5G-CN 152 by means of an NG interface and to other basestations by an Xn interface. The NG and Xn interfaces may be establishedusing direct physical connections and/or indirect connections over anunderlying transport network, such as an internet protocol (IP)transport network. The gNBs 160 and/or the ng-eNBs 162 may be connectedto the UEs 156 by means of a Uu interface. For example, as illustratedin FIG. 1B, gNB 160A may be connected to the UE 156A by means of a Uuinterface. The NG, Xn, and Uu interfaces are associated with a protocolstack. The protocol stacks associated with the interfaces may be used bythe network elements in FIG. 1B to exchange data and signaling messagesand may include two planes: a user plane and a control plane. The userplane may handle data of interest to a user. The control plane mayhandle signaling messages of interest to the network elements.

The gNBs 160 and/or the ng-eNBs 162 may be connected to one or moreAMF/UPF functions of the 5G-CN 152, such as the AMF/UPF 158, by means ofone or more NG interfaces. For example, the gNB 160A may be connected tothe UPF 158B of the AMF/UPF 158 by means of an NG-User plane (NG-U)interface. The NG-U interface may provide delivery (e.g., non-guaranteeddelivery) of user plane PDUs between the gNB 160A and the UPF 158B. ThegNB 160A may be connected to the AMF 158A by means of an NG-Controlplane (NG-C) interface. The NG-C interface may provide, for example, NGinterface management, UE context management, UE mobility management,transport of NAS messages, paging, PDU session management, andconfiguration transfer and/or warning message transmission.

The gNBs 160 may provide NR user plane and control plane protocolterminations towards the UEs 156 over the Uu interface. For example, thegNB 160A may provide NR user plane and control plane protocolterminations toward the UE 156A over a Uu interface associated with afirst protocol stack. The ng-eNBs 162 may provide Evolved UMTSTerrestrial Radio Access (E-UTRA) user plane and control plane protocolterminations towards the UEs 156 over a Uu interface, where E-UTRArefers to the 3GPP 4G radio-access technology. For example, the ng-eNB162B may provide E-UTRA user plane and control plane protocolterminations towards the UE 156B over a Uu interface associated with asecond protocol stack.

The 5G-CN 152 was described as being configured to handle NR and 4Gradio accesses. It will be appreciated by one of ordinary skill in theart that it may be possible for NR to connect to a 4G core network in amode known as “non-standalone operation.” In non-standalone operation, a4G core network is used to provide (or at least support) control-planefunctionality (e.g., initial access, mobility, and paging). Althoughonly one AMF/UPF 158 is shown in FIG. 1B, one gNB or ng-eNB may beconnected to multiple AMF/UPF nodes to provide redundancy and/or to loadshare across the multiple AMF/UPF nodes.

As discussed, an interface (e.g., Uu, Xn, and NG interfaces) between thenetwork elements in FIG. 1B may be associated with a protocol stack thatthe network elements use to exchange data and signaling messages. Aprotocol stack may include two planes: a user plane and a control plane.The user plane may handle data of interest to a user, and the controlplane may handle signaling messages of interest to the network elements.

FIG. 2A and FIG. 2B respectively illustrate examples of NR user planeand NR control plane protocol stacks for the Uu interface that liesbetween a UE 210 and a gNB 220. The protocol stacks illustrated in FIG.2A and FIG. 2B may be the same or similar to those used for the Uuinterface between, for example, the UE 156A and the gNB 160A shown inFIG. 1B.

FIG. 2A illustrates a NR user plane protocol stack comprising fivelayers implemented in the UE 210 and the gNB 220. At the bottom of theprotocol stack, physical layers (PHYs) 211 and 221 may provide transportservices to the higher layers of the protocol stack and may correspondto layer 1 of the Open Systems Interconnection (OSI) model. The nextfour protocols above PHYs 211 and 221 comprise media access controllayers (MACs) 212 and 222, radio link control layers (RLCs) 213 and 223,packet data convergence protocol layers (PDCPs) 214 and 224, and servicedata application protocol layers (SDAPs) 215 and 225. Together, thesefour protocols may make up layer 2, or the data link layer, of the OSImodel.

FIG. 3 illustrates an example of services provided between protocollayers of the NR user plane protocol stack. Starting from the top ofFIG. 2A and FIG. 3, the SDAPs 215 and 225 may perform QoS flow handling.The UE 210 may receive services through a PDU session, which may be alogical connection between the UE 210 and a DN. The PDU session may haveone or more QoS flows. A UPF of a CN (e.g., the UPF 158B) may map IPpackets to the one or more QoS flows of the PDU session based on QoSrequirements (e.g., in terms of delay, data rate, and/or error rate).The SDAPs 215 and 225 may perform mapping/de-mapping between the one ormore QoS flows and one or more data radio bearers. Themapping/de-mapping between the QoS flows and the data radio bearers maybe determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210may be informed of the mapping between the QoS flows and the data radiobearers through reflective mapping or control signaling received fromthe gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 maymark the downlink packets with a QoS flow indicator (QFI), which may beobserved by the SDAP 215 at the UE 210 to determine themapping/de-mapping between the QoS flows and the data radio bearers.

The PDCPs 214 and 224 may perform header compression/decompression toreduce the amount of data that needs to be transmitted over the airinterface, ciphering/deciphering to prevent unauthorized decoding ofdata transmitted over the air interface, and integrity protection (toensure control messages originate from intended sources. The PDCPs 214and 224 may perform retransmissions of undelivered packets, in-sequencedelivery and reordering of packets, and removal of packets received induplicate due to, for example, an intra-gNB handover. The PDCPs 214 and224 may perform packet duplication to improve the likelihood of thepacket being received and, at the receiver, remove any duplicatepackets. Packet duplication may be useful for services that require highreliability.

Although not shown in FIG. 3, PDCPs 214 and 224 may performmapping/de-mapping between a split radio bearer and RLC channels in adual connectivity scenario. Dual connectivity is a technique that allowsa UE to connect to two cells or, more generally, two cell groups: amaster cell group (MCG) and a secondary cell group (SCG). A split beareris when a single radio bearer, such as one of the radio bearers providedby the PDCPs 214 and 224 as a service to the SDAPs 215 and 225, ishandled by cell groups in dual connectivity. The PDCPs 214 and 224 maymap/de-map the split radio bearer between RLC channels belonging to cellgroups.

The RLCs 213 and 223 may perform segmentation, retransmission throughAutomatic Repeat Request (ARQ), and removal of duplicate data unitsreceived from MACs 212 and 222, respectively. The RLCs 213 and 223 maysupport three transmission modes: transparent mode (TM); unacknowledgedmode (UM); and acknowledged mode (AM). Based on the transmission mode anRLC is operating, the RLC may perform one or more of the notedfunctions. The RLC configuration may be per logical channel with nodependency on numerologies and/or Transmission Time Interval (TTI)durations. As shown in FIG. 3, the RLCs 213 and 223 may provide RLCchannels as a service to PDCPs 214 and 224, respectively.

The MACs 212 and 222 may perform multiplexing/demultiplexing of logicalchannels and/or mapping between logical channels and transport channels.The multiplexing/demultiplexing may include multiplexing/demultiplexingof data units, belonging to the one or more logical channels, into/fromTransport Blocks (TBs) delivered to/from the PHYs 211 and 221. The MAC222 may be configured to perform scheduling, scheduling informationreporting, and priority handling between UEs by means of dynamicscheduling. Scheduling may be performed in the gNB 220 (at the MAC 222)for downlink and uplink. The MACs 212 and 222 may be configured toperform error correction through Hybrid Automatic Repeat Request (HARQ)(e.g., one HARQ entity per carrier in case of Carrier Aggregation (CA)),priority handling between logical channels of the UE 210 by means oflogical channel prioritization, and/or padding. The MACs 212 and 222 maysupport one or more numerologies and/or transmission timings. In anexample, mapping restrictions in a logical channel prioritization maycontrol which numerology and/or transmission timing a logical channelmay use. As shown in FIG. 3, the MACs 212 and 222 may provide logicalchannels as a service to the RLCs 213 and 223.

The PHYs 211 and 221 may perform mapping of transport channels tophysical channels and digital and analog signal processing functions forsending and receiving information over the air interface. These digitaland analog signal processing functions may include, for example,coding/decoding and modulation/demodulation. The PHYs 211 and 221 mayperform multi-antenna mapping. As shown in FIG. 3, the PHYs 211 and 221may provide one or more transport channels as a service to the MACs 212and 222.

FIG. 4A illustrates an example downlink data flow through the NR userplane protocol stack. FIG. 4A illustrates a downlink data flow of threeIP packets (n, n+1, and m) through the NR user plane protocol stack togenerate two TBs at the gNB 220. An uplink data flow through the NR userplane protocol stack may be similar to the downlink data flow depictedin FIG. 4A.

The downlink data flow of FIG. 4A begins when SDAP 225 receives thethree IP packets from one or more QoS flows and maps the three packetsto radio bearers. In FIG. 4A, the SDAP 225 maps IP packets n and n+1 toa first radio bearer 402 and maps IP packet m to a second radio bearer404. An SDAP header (labeled with an “H” in FIG. 4A) is added to an IPpacket. The data unit from/to a higher protocol layer is referred to asa service data unit (SDU) of the lower protocol layer and the data unitto/from a lower protocol layer is referred to as a protocol data unit(PDU) of the higher protocol layer. As shown in FIG. 4A, the data unitfrom the SDAP 225 is an SDU of lower protocol layer PDCP 224 and is aPDU of the SDAP 225.

The remaining protocol layers in FIG. 4A may perform their associatedfunctionality (e.g., with respect to FIG. 3), add corresponding headers,and forward their respective outputs to the next lower layer. Forexample, the PDCP 224 may perform IP-header compression and cipheringand forward its output to the RLC 223. The RLC 223 may optionallyperform segmentation (e.g., as shown for IP packet m in FIG. 4A) andforward its output to the MAC 222. The MAC 222 may multiplex a number ofRLC PDUs and may attach a MAC subheader to an RLC PDU to form atransport block. In NR, the MAC subheaders may be distributed across theMAC PDU, as illustrated in FIG. 4A. In LTE, the MAC subheaders may beentirely located at the beginning of the MAC PDU. The NR MAC PDUstructure may reduce processing time and associated latency because theMAC PDU subheaders may be computed before the full MAC PDU is assembled.

FIG. 4B illustrates an example format of a MAC subheader in a MAC PDU.The MAC subheader includes: an SDU length field for indicating thelength (e.g., in bytes) of the MAC SDU to which the MAC subheadercorresponds; a logical channel identifier (LCID) field for identifyingthe logical channel from which the MAC SDU originated to aid in thedemultiplexing process; a flag (F) for indicating the size of the SDUlength field; and a reserved bit (R) field for future use.

FIG. 4B further illustrates MAC control elements (CEs) inserted into theMAC PDU by a MAC, such as MAC 223 or MAC 222. For example, FIG. 4Billustrates two MAC CEs inserted into the MAC PDU. MAC CEs may beinserted at the beginning of a MAC PDU for downlink transmissions (asshown in FIG. 4B) and at the end of a MAC PDU for uplink transmissions.MAC CEs may be used for in-band control signaling. Example MAC CEsinclude: scheduling-related MAC CEs, such as buffer status reports andpower headroom reports; activation/deactivation MAC CEs, such as thosefor activation/deactivation of PDCP duplication detection, channel stateinformation (CSI) reporting, sounding reference signal (SRS)transmission, and prior configured components; discontinuous reception(DRX) related MAC CEs; timing advance MAC CEs; and random access relatedMAC CEs. A MAC CE may be preceded by a MAC subheader with a similarformat as described for MAC SDUs and may be identified with a reservedvalue in the LCID field that indicates the type of control informationincluded in the MAC CE.

Before describing the NR control plane protocol stack, logical channels,transport channels, and physical channels are first described as well asa mapping between the channel types. One or more of the channels may beused to carry out functions associated with the NR control planeprotocol stack described later below.

FIG. 5A and FIG. 5B illustrate, for downlink and uplink respectively, amapping between logical channels, transport channels, and physicalchannels. Information is passed through channels between the RLC, theMAC, and the PHY of the NR protocol stack. A logical channel may be usedbetween the RLC and the MAC and may be classified as a control channelthat carries control and configuration information in the NR controlplane or as a traffic channel that carries data in the NR user plane. Alogical channel may be classified as a dedicated logical channel that isdedicated to a specific UE or as a common logical channel that may beused by more than one UE. A logical channel may also be defined by thetype of information it carries. The set of logical channels defined byNR include, for example:

-   -   a paging control channel (PCCH) for carrying paging messages        used to page a UE whose location is not known to the network on        a cell level;    -   a broadcast control channel (BCCH) for carrying system        information messages in the form of a master information block        (MIB) and several system information blocks (SIBs), wherein the        system information messages may be used by the UEs to obtain        information about how a cell is configured and how to operate        within the cell;    -   a common control channel (CCCH) for carrying control messages        together with random access;    -   a dedicated control channel (DCCH) for carrying control messages        to/from a specific the UE to configure the UE; and    -   a dedicated traffic channel (DTCH) for carrying user data        to/from a specific the UE.

Transport channels are used between the MAC and PHY layers and may bedefined by how the information they carry is transmitted over the airinterface. The set of transport channels defined by NR include, forexample:

-   -   a paging channel (PCH) for carrying paging messages that        originated from the PCCH;    -   a broadcast channel (BCH) for carrying the MIB from the BCCH;    -   a downlink shared channel (DL-SCH) for carrying downlink data        and signaling messages, including the SIBs from the BCCH;    -   an uplink shared channel (UL-SCH) for carrying uplink data and        signaling messages; and    -   a random access channel (RACH) for allowing a UE to contact the        network without any prior scheduling.

The PHY may use physical channels to pass information between processinglevels of the PHY. A physical channel may have an associated set oftime-frequency resources for carrying the information of one or moretransport channels. The PHY may generate control information to supportthe low-level operation of the PHY and provide the control informationto the lower levels of the PHY via physical control channels, known asL1/L2 control channels. The set of physical channels and physicalcontrol channels defined by NR include, for example:

-   -   a physical broadcast channel (PBCH) for carrying the MIB from        the BCH;    -   a physical downlink shared channel (PDSCH) for carrying downlink        data and signaling messages from the DL-SCH, as well as paging        messages from the PCH;    -   a physical downlink control channel (PDCCH) for carrying        downlink control information (DCI), which may include downlink        scheduling commands, uplink scheduling grants, and uplink power        control commands;    -   a physical uplink shared channel (PUSCH) for carrying uplink        data and signaling messages from the UL-SCH and in some        instances uplink control information (UCI) as described below;    -   a physical uplink control channel (PUCCH) for carrying UCI,        which may include HARQ acknowledgments, channel quality        indicators (CQI), pre-coding matrix indicators (PMI), rank        indicators (RI), and scheduling requests (SR); and    -   a physical random access channel (PRACH) for random access.

Similar to the physical control channels, the physical layer generatesphysical signals to support the low-level operation of the physicallayer. As shown in FIG. 5A and FIG. 5B, the physical layer signalsdefined by NR include: primary synchronization signals (PSS), secondarysynchronization signals (SSS), channel state information referencesignals (CSI-RS), demodulation reference signals (DMRS), soundingreference signals (SRS), and phase-tracking reference signals (PT-RS).These physical layer signals will be described in greater detail below.

FIG. 2B illustrates an example NR control plane protocol stack. As shownin FIG. 2B, the NR control plane protocol stack may use the same/similarfirst four protocol layers as the example NR user plane protocol stack.These four protocol layers include the PHYs 211 and 221, the MACs 212and 222, the RLCs 213 and 223, and the PDCPs 214 and 224. Instead ofhaving the SDAPs 215 and 225 at the top of the stack as in the NR userplane protocol stack, the NR control plane stack has radio resourcecontrols (RRCs) 216 and 226 and NAS protocols 217 and 237 at the top ofthe NR control plane protocol stack.

The NAS protocols 217 and 237 may provide control plane functionalitybetween the UE 210 and the AMF 230 (e.g., the AMF 158A) or, moregenerally, between the UE 210 and the CN. The NAS protocols 217 and 237may provide control plane functionality between the UE 210 and the AMF230 via signaling messages, referred to as NAS messages. There is nodirect path between the UE 210 and the AMF 230 through which the NASmessages can be transported. The NAS messages may be transported usingthe AS of the Uu and NG interfaces. NAS protocols 217 and 237 mayprovide control plane functionality such as authentication, security,connection setup, mobility management, and session management.

The RRCs 216 and 226 may provide control plane functionality between theUE 210 and the gNB 220 or, more generally, between the UE 210 and theRAN. The RRCs 216 and 226 may provide control plane functionalitybetween the UE 210 and the gNB 220 via signaling messages, referred toas RRC messages. RRC messages may be transmitted between the UE 210 andthe RAN using signaling radio bearers and the same/similar PDCP, RLC,MAC, and PHY protocol layers. The MAC may multiplex control-plane anduser-plane data into the same transport block (TB). The RRCs 216 and 226may provide control plane functionality such as: broadcast of systeminformation related to AS and NAS; paging initiated by the CN or theRAN; establishment, maintenance and release of an RRC connection betweenthe UE 210 and the RAN; security functions including key management;establishment, configuration, maintenance and release of signaling radiobearers and data radio bearers; mobility functions; QoS managementfunctions; the UE measurement reporting and control of the reporting;detection of and recovery from radio link failure (RLF); and/or NASmessage transfer. As part of establishing an RRC connection, RRCs 216and 226 may establish an RRC context, which may involve configuringparameters for communication between the UE 210 and the RAN.

FIG. 6 is an example diagram showing RRC state transitions of a UE. TheUE may be the same or similar to the wireless device 106 depicted inFIG. 1A, the UE 210 depicted in FIG. 2A and FIG. 2B, or any otherwireless device described in the present disclosure. As illustrated inFIG. 6, a UE may be in at least one of three RRC states: RRC connected602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRCinactive 606 (e.g., RRC_INACTIVE).

In RRC connected 602, the UE has an established RRC context and may haveat least one RRC connection with a base station. The base station may besimilar to one of the one or more base stations included in the RAN 104depicted in FIG. 1A, one of the gNBs 160 or ng-eNBs 162 depicted in FIG.1B, the gNB 220 depicted in FIG. 2A and FIG. 2B, or any other basestation described in the present disclosure. The base station with whichthe UE is connected may have the RRC context for the UE. The RRCcontext, referred to as the UE context, may comprise parameters forcommunication between the UE and the base station. These parameters mayinclude, for example: one or more AS contexts; one or more radio linkconfiguration parameters; bearer configuration information (e.g.,relating to a data radio bearer, signaling radio bearer, logicalchannel, QoS flow, and/or PDU session); security information; and/orPHY, MAC, RLC, PDCP, and/or SDAP layer configuration information. Whilein RRC connected 602, mobility of the UE may be managed by the RAN(e.g., the RAN 104 or the NG-RAN 154). The UE may measure the signallevels (e.g., reference signal levels) from a serving cell andneighboring cells and report these measurements to the base stationcurrently serving the UE. The UE's serving base station may request ahandover to a cell of one of the neighboring base stations based on thereported measurements. The RRC state may transition from RRC connected602 to RRC idle 604 through a connection release procedure 608 or to RRCinactive 606 through a connection inactivation procedure 610.

In RRC idle 604, an RRC context may not be established for the UE. InRRC idle 604, the UE may not have an RRC connection with the basestation. While in RRC idle 604, the UE may be in a sleep state for themajority of the time (e.g., to conserve battery power). The UE may wakeup periodically (e.g., once in every discontinuous reception cycle) tomonitor for paging messages from the RAN. Mobility of the UE may bemanaged by the UE through a procedure known as cell reselection. The RRCstate may transition from RRC idle 604 to RRC connected 602 through aconnection establishment procedure 612, which may involve a randomaccess procedure as discussed in greater detail below.

In RRC inactive 606, the RRC context previously established ismaintained in the UE and the base station. This allows for a fasttransition to RRC connected 602 with reduced signaling overhead ascompared to the transition from RRC idle 604 to RRC connected 602. Whilein RRC inactive 606, the UE may be in a sleep state and mobility of theUE may be managed by the UE through cell reselection. The RRC state maytransition from RRC inactive 606 to RRC connected 602 through aconnection resume procedure 614 or to RRC idle 604 though a connectionrelease procedure 616 that may be the same as or similar to connectionrelease procedure 608.

An RRC state may be associated with a mobility management mechanism. InRRC idle 604 and RRC inactive 606, mobility is managed by the UE throughcell reselection. The purpose of mobility management in RRC idle 604 andRRC inactive 606 is to allow the network to be able to notify the UE ofan event via a paging message without having to broadcast the pagingmessage over the entire mobile communications network. The mobilitymanagement mechanism used in RRC idle 604 and RRC inactive 606 may allowthe network to track the UE on a cell-group level so that the pagingmessage may be broadcast over the cells of the cell group that the UEcurrently resides within instead of the entire mobile communicationnetwork. The mobility management mechanisms for RRC idle 604 and RRCinactive 606 track the UE on a cell-group level. They may do so usingdifferent granularities of grouping. For example, there may be threelevels of cell-grouping granularity: individual cells; cells within aRAN area identified by a RAN area identifier (RAI); and cells within agroup of RAN areas, referred to as a tracking area and identified by atracking area identifier (TAI).

Tracking areas may be used to track the UE at the CN level. The CN(e.g., the CN 102 or the 5G-CN 152) may provide the UE with a list ofTAIs associated with a UE registration area. If the UE moves, throughcell reselection, to a cell associated with a TAI not included in thelist of TAIs associated with the UE registration area, the UE mayperform a registration update with the CN to allow the CN to update theUE's location and provide the UE with a new the UE registration area.

RAN areas may be used to track the UE at the RAN level. For a UE in RRCinactive 606 state, the UE may be assigned a RAN notification area. ARAN notification area may comprise one or more cell identities, a listof RAIs, or a list of TAIs. In an example, a base station may belong toone or more RAN notification areas. In an example, a cell may belong toone or more RAN notification areas. If the UE moves, through cellreselection, to a cell not included in the RAN notification areaassigned to the UE, the UE may perform a notification area update withthe RAN to update the UE's RAN notification area.

A base station storing an RRC context for a UE or a last serving basestation of the UE may be referred to as an anchor base station. Ananchor base station may maintain an RRC context for the UE at leastduring a period of time that the UE stays in a RAN notification area ofthe anchor base station and/or during a period of time that the UE staysin RRC inactive 606.

A gNB, such as gNBs 160 in FIG. 1B, may be split in two parts: a centralunit (gNB-CU), and one or more distributed units (gNB-DU). A gNB-CU maybe coupled to one or more gNB-DUs using an F1 interface. The gNB-CU maycomprise the RRC, the PDCP, and the SDAP. A gNB-DU may comprise the RLC,the MAC, and the PHY.

In NR, the physical signals and physical channels (discussed withrespect to FIG. 5A and FIG. 5B) may be mapped onto orthogonal frequencydivisional multiplexing (OFDM) symbols. OFDM is a multicarriercommunication scheme that transmits data over F orthogonal subcarriers(or tones). Before transmission, the data may be mapped to a series ofcomplex symbols (e.g., M-quadrature amplitude modulation (M-QAM) orM-phase shift keying (M-PSK) symbols), referred to as source symbols,and divided into F parallel symbol streams. The F parallel symbolstreams may be treated as though they are in the frequency domain andused as inputs to an Inverse Fast Fourier Transform (IFFT) block thattransforms them into the time domain. The IFFT block may take in Fsource symbols at a time, one from each of the F parallel symbolstreams, and use each source symbol to modulate the amplitude and phaseof one of F sinusoidal basis functions that correspond to the Forthogonal subcarriers. The output of the IFFT block may be Ftime-domain samples that represent the summation of the F orthogonalsubcarriers. The F time-domain samples may form a single OFDM symbol.After some processing (e.g., addition of a cyclic prefix) andup-conversion, an OFDM symbol provided by the IFFT block may betransmitted over the air interface on a carrier frequency. The Fparallel symbol streams may be mixed using an FFT block before beingprocessed by the IFFT block. This operation produces Discrete FourierTransform (DFT)-precoded OFDM symbols and may be used by UEs in theuplink to reduce the peak to average power ratio (PAPR). Inverseprocessing may be performed on the OFDM symbol at a receiver using anFFT block to recover the data mapped to the source symbols.

FIG. 7 illustrates an example configuration of an NR frame into whichOFDM symbols are grouped. An NR frame may be identified by a systemframe number (SFN). The SFN may repeat with a period of 1024 frames. Asillustrated, one NR frame may be 10 milliseconds (ms) in duration andmay include 10 subframes that are 1 ms in duration. A subframe may bedivided into slots that include, for example, 14 OFDM symbols per slot.

The duration of a slot may depend on the numerology used for the OFDMsymbols of the slot. In NR, a flexible numerology is supported toaccommodate different cell deployments (e.g., cells with carrierfrequencies below 1 GHz up to cells with carrier frequencies in themm-wave range). A numerology may be defined in terms of subcarrierspacing and cyclic prefix duration. For a numerology in NR, subcarrierspacings may be scaled up by powers of two from a baseline subcarrierspacing of 15 kHz, and cyclic prefix durations may be scaled down bypowers of two from a baseline cyclic prefix duration of 4.7 μs. Forexample, NR defines numerologies with the following subcarrierspacing/cyclic prefix duration combinations: 15 kHz/4.7 μs; 30 kHz/2.3μs; 60 kHz/1.2 μs; 120 kHz/0.59 μs; and 240 kHz/0.29 μs.

A slot may have a fixed number of OFDM symbols (e.g., 14 OFDM symbols).A numerology with a higher subcarrier spacing has a shorter slotduration and, correspondingly, more slots per subframe. FIG. 7illustrates this numerology-dependent slot duration andslots-per-subframe transmission structure (the numerology with asubcarrier spacing of 240 kHz is not shown in FIG. 7 for ease ofillustration). A subframe in NR may be used as a numerology-independenttime reference, while a slot may be used as the unit upon which uplinkand downlink transmissions are scheduled. To support low latency,scheduling in NR may be decoupled from the slot duration and start atany OFDM symbol and last for as many symbols as needed for atransmission. These partial slot transmissions may be referred to asmini-slot or subslot transmissions.

FIG. 8 illustrates an example configuration of a slot in the time andfrequency domain for an NR carrier. The slot includes resource elements(REs) and resource blocks (RBs). An RE is the smallest physical resourcein NR. An RE spans one OFDM symbol in the time domain by one subcarrierin the frequency domain as shown in FIG. 8. An RB spans twelveconsecutive REs in the frequency domain as shown in FIG. 8. An NRcarrier may be limited to a width of 275 RBs or 275×12=3300 subcarriers.Such a limitation, if used, may limit the NR carrier to 50, 100, 200,and 400 MHz for subcarrier spacings of 15, 30, 60, and 120 kHz,respectively, where the 400 MHz bandwidth may be set based on a 400 MHzper carrier bandwidth limit.

FIG. 8 illustrates a single numerology being used across the entirebandwidth of the NR carrier. In other example configurations, multiplenumerologies may be supported on the same carrier.

NR may support wide carrier bandwidths (e.g., up to 400 MHz for asubcarrier spacing of 120 kHz). Not all UEs may be able to receive thefull carrier bandwidth (e.g., due to hardware limitations). Also,receiving the full carrier bandwidth may be prohibitive in terms of UEpower consumption. In an example, to reduce power consumption and/or forother purposes, a UE may adapt the size of the UE's receive bandwidthbased on the amount of traffic the UE is scheduled to receive. This isreferred to as bandwidth adaptation.

NR defines bandwidth parts (BWPs) to support UEs not capable ofreceiving the full carrier bandwidth and to support bandwidthadaptation. In an example, a BWP may be defined by a subset ofcontiguous RBs on a carrier. A UE may be configured (e.g., via RRClayer) with one or more downlink BWPs and one or more uplink BWPs perserving cell (e.g., up to four downlink BWPs and up to four uplink BWPsper serving cell). At a given time, one or more of the configured BWPsfor a serving cell may be active. These one or more BWPs may be referredto as active BWPs of the serving cell. When a serving cell is configuredwith a secondary uplink carrier, the serving cell may have one or morefirst active BWPs in the uplink carrier and one or more second activeBWPs in the secondary uplink carrier.

For unpaired spectra, a downlink BWP from a set of configured downlinkBWPs may be linked with an uplink BWP from a set of configured uplinkBWPs if a downlink BWP index of the downlink BWP and an uplink BWP indexof the uplink BWP are the same. For unpaired spectra, a UE may expectthat a center frequency for a downlink BWP is the same as a centerfrequency for an uplink BWP.

For a downlink BWP in a set of configured downlink BWPs on a primarycell (PCell), a base station may configure a UE with one or more controlresource sets (CORESETs) for at least one search space. A search spaceis a set of locations in the time and frequency domains where the UE mayfind control information. The search space may be a UE-specific searchspace or a common search space (potentially usable by a plurality ofUEs). For example, a base station may configure a UE with a commonsearch space, on a PCell or on a primary secondary cell (PSCell), in anactive downlink BWP.

For an uplink BWP in a set of configured uplink BWPs, a BS may configurea UE with one or more resource sets for one or more PUCCH transmissions.A UE may receive downlink receptions (e.g., PDCCH or PDSCH) in adownlink BWP according to a configured numerology (e.g., subcarrierspacing and cyclic prefix duration) for the downlink BWP. The UE maytransmit uplink transmissions (e.g., PUCCH or PUSCH) in an uplink BWPaccording to a configured numerology (e.g., subcarrier spacing andcyclic prefix length for the uplink BWP).

One or more BWP indicator fields may be provided in Downlink ControlInformation (DCI). A value of a BWP indicator field may indicate whichBWP in a set of configured BWPs is an active downlink BWP for one ormore downlink receptions. The value of the one or more BWP indicatorfields may indicate an active uplink BWP for one or more uplinktransmissions.

A base station may semi-statically configure a UE with a defaultdownlink BWP within a set of configured downlink BWPs associated with aPCell. If the base station does not provide the default downlink BWP tothe UE, the default downlink BWP may be an initial active downlink BWP.The UE may determine which BWP is the initial active downlink BWP basedon a CORESET configuration obtained using the PBCH.

A base station may configure a UE with a BWP inactivity timer value fora PCell. The UE may start or restart a BWP inactivity timer at anyappropriate time. For example, the UE may start or restart the BWPinactivity timer (a) when the UE detects a DCI indicating an activedownlink BWP other than a default downlink BWP for a paired spectraoperation; or (b) when a UE detects a DCI indicating an active downlinkBWP or active uplink BWP other than a default downlink BWP or uplink BWPfor an unpaired spectra operation. If the UE does not detect DCI duringan interval of time (e.g., 1 ms or 0.5 ms), the UE may run the BWPinactivity timer toward expiration (for example, increment from zero tothe BWP inactivity timer value, or decrement from the BWP inactivitytimer value to zero). When the BWP inactivity timer expires, the UE mayswitch from the active downlink BWP to the default downlink BWP.

In an example, a base station may semi-statically configure a UE withone or more BWPs. A UE may switch an active BWP from a first BWP to asecond BWP in response to receiving a DCI indicating the second BWP asan active BWP and/or in response to an expiry of the BWP inactivitytimer (e.g., if the second BWP is the default BWP).

Downlink and uplink BWP switching (where BWP switching refers toswitching from a currently active BWP to a not currently active BWP) maybe performed independently in paired spectra. In unpaired spectra,downlink and uplink BWP switching may be performed simultaneously.Switching between configured BWPs may occur based on RRC signaling, DCI,expiration of a BWP inactivity timer, and/or an initiation of randomaccess.

FIG. 9 illustrates an example of bandwidth adaptation using threeconfigured BWPs for an NR carrier. A UE configured with the three BWPsmay switch from one BWP to another BWP at a switching point. In theexample illustrated in FIG. 9, the BWPs include: a BWP 902 with abandwidth of 40 MHz and a subcarrier spacing of 15 kHz; a BWP 904 with abandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and a BWP 906with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. The BWP902 may be an initial active BWP, and the BWP 904 may be a default BWP.The UE may switch between BWPs at switching points. In the example ofFIG. 9, the UE may switch from the BWP 902 to the BWP 904 at a switchingpoint 908. The switching at the switching point 908 may occur for anysuitable reason, for example, in response to an expiry of a BWPinactivity timer (indicating switching to the default BWP) and/or inresponse to receiving a DCI indicating BWP 904 as the active BWP. The UEmay switch at a switching point 910 from active BWP 904 to BWP 906 inresponse receiving a DCI indicating BWP 906 as the active BWP. The UEmay switch at a switching point 912 from active BWP 906 to BWP 904 inresponse to an expiry of a BWP inactivity timer and/or in responsereceiving a DCI indicating BWP 904 as the active BWP. The UE may switchat a switching point 914 from active BWP 904 to BWP 902 in responsereceiving a DCI indicating BWP 902 as the active BWP.

If a UE is configured for a secondary cell with a default downlink BWPin a set of configured downlink BWPs and a timer value, UE proceduresfor switching BWPs on a secondary cell may be the same/similar as thoseon a primary cell. For example, the UE may use the timer value and thedefault downlink BWP for the secondary cell in the same/similar manneras the UE would use these values for a primary cell.

To provide for greater data rates, two or more carriers can beaggregated and simultaneously transmitted to/from the same UE usingcarrier aggregation (CA). The aggregated carriers in CA may be referredto as component carriers (CCs). When CA is used, there are a number ofserving cells for the UE, one for a CC. The CCs may have threeconfigurations in the frequency domain.

FIG. 10A illustrates the three CA configurations with two CCs. In theintraband, contiguous configuration 1002, the two CCs are aggregated inthe same frequency band (frequency band A) and are located directlyadjacent to each other within the frequency band. In the intraband,non-contiguous configuration 1004, the two CCs are aggregated in thesame frequency band (frequency band A) and are separated in thefrequency band by a gap. In the interband configuration 1006, the twoCCs are located in frequency bands (frequency band A and frequency bandB).

In an example, up to 32 CCs may be aggregated. The aggregated CCs mayhave the same or different bandwidths, subcarrier spacing, and/orduplexing schemes (TDD or FDD). A serving cell for a UE using CA mayhave a downlink CC. For FDD, one or more uplink CCs may be optionallyconfigured for a serving cell. The ability to aggregate more downlinkcarriers than uplink carriers may be useful, for example, when the UEhas more data traffic in the downlink than in the uplink.

When CA is used, one of the aggregated cells for a UE may be referred toas a primary cell (PCell). The PCell may be the serving cell that the UEinitially connects to at RRC connection establishment, reestablishment,and/or handover. The PCell may provide the UE with NAS mobilityinformation and the security input. UEs may have different PCells. Inthe downlink, the carrier corresponding to the PCell may be referred toas the downlink primary CC (DL PCC). In the uplink, the carriercorresponding to the PCell may be referred to as the uplink primary CC(UL PCC). The other aggregated cells for the UE may be referred to assecondary cells (SCells). In an example, the SCells may be configuredafter the PCell is configured for the UE. For example, an SCell may beconfigured through an RRC Connection Reconfiguration procedure. In thedownlink, the carrier corresponding to an SCell may be referred to as adownlink secondary CC (DL SCC). In the uplink, the carrier correspondingto the SCell may be referred to as the uplink secondary CC (UL SCC).

Configured SCells for a UE may be activated and deactivated based on,for example, traffic and channel conditions. Deactivation of an SCellmay mean that PDCCH and PDSCH reception on the SCell is stopped andPUSCH, SRS, and CQI transmissions on the SCell are stopped. ConfiguredSCells may be activated and deactivated using a MAC CE with respect toFIG. 4B. For example, a MAC CE may use a bitmap (e.g., one bit perSCell) to indicate which SCells (e.g., in a subset of configured SCells)for the UE are activated or deactivated. Configured SCells may bedeactivated in response to an expiration of an SCell deactivation timer(e.g., one SCell deactivation timer per SCell).

Downlink control information, such as scheduling assignments andscheduling grants, for a cell may be transmitted on the cellcorresponding to the assignments and grants, which is known asself-scheduling. The DCI for the cell may be transmitted on anothercell, which is known as cross-carrier scheduling. Uplink controlinformation (e.g., HARQ acknowledgments and channel state feedback, suchas CQI, PMI, and/or RI) for aggregated cells may be transmitted on thePUCCH of the PCell. For a larger number of aggregated downlink CCs, thePUCCH of the PCell may become overloaded. Cells may be divided intomultiple PUCCH groups.

FIG. 10B illustrates an example of how aggregated cells may beconfigured into one or more PUCCH groups. A PUCCH group 1010 and a PUCCHgroup 1050 may include one or more downlink CCs, respectively. In theexample of FIG. 10B, the PUCCH group 1010 includes three downlink CCs: aPcell1011, an Scell1012, and an Scell1013. The PUCCH group 1050 includesthree downlink CCs in the present example: a Pcell1051, an Scell1052,and an Scell1053. One or more uplink CCs may be configured as aPcell1021, an Scell1022, and an Scell1023. One or more other uplink CCsmay be configured as a primary Scell (PSCell) 1061, an Scell1062, and anScell1063. Uplink control information (UCI) related to the downlink CCsof the PUCCH group 1010, shown as UCI 1031, UCI 1032, and UCI 1033, maybe transmitted in the uplink of the Pcell1021. Uplink controlinformation (UCI) related to the downlink CCs of the PUCCH group 1050,shown as UCI 1071, UCI 1072, and UCI 1073, may be transmitted in theuplink of the PScell1061. In an example, if the aggregated cellsdepicted in FIG. 10B were not divided into the PUCCH group 1010 and thePUCCH group 1050, a single uplink PCell to transmit UCI relating to thedownlink CCs, and the PCell may become overloaded. By dividingtransmissions of UCI between the Pcell1021 and the PScell1061,overloading may be prevented.

A cell, comprising a downlink carrier and optionally an uplink carrier,may be assigned with a physical cell ID and a cell index. The physicalcell ID or the cell index may identify a downlink carrier and/or anuplink carrier of the cell, for example, depending on the context inwhich the physical cell ID is used. A physical cell ID may be determinedusing a synchronization signal transmitted on a downlink componentcarrier. A cell index may be determined using RRC messages. In thedisclosure, a physical cell ID may be referred to as a carrier ID, and acell index may be referred to as a carrier index. For example, when thedisclosure refers to a first physical cell ID for a first downlinkcarrier, the disclosure may mean the first physical cell ID is for acell comprising the first downlink carrier. The same/similar concept mayapply to, for example, a carrier activation. When the disclosureindicates that a first carrier is activated, the specification may meanthat a cell comprising the first carrier is activated.

In CA, a multi-carrier nature of a PHY may be exposed to a MAC. In anexample, a HARQ entity may operate on a serving cell. A transport blockmay be generated per assignment/grant per serving cell. A transportblock and potential HARQ retransmissions of the transport block may bemapped to a serving cell.

In the downlink, a base station may transmit (e.g., unicast, multicast,and/or broadcast) one or more Reference Signals (RSs) to a UE (e.g.,PSS, SSS, CSI-RS, DMRS, and/or PT-RS, as shown in FIG. 5A). In theuplink, the UE may transmit one or more RSs to the base station (e.g.,DMRS, PT-RS, and/or SRS, as shown in FIG. 5B). The PSS and the SSS maybe transmitted by the base station and used by the UE to synchronize theUE to the base station. The PSS and the SSS may be provided in asynchronization signal (SS)/physical broadcast channel (PBCH) block thatincludes the PSS, the SSS, and the PBCH. The base station mayperiodically transmit a burst of SS/PBCH blocks.

FIG. 11A illustrates an example of an SS/PBCH block's structure andlocation. A burst of SS/PBCH blocks may include one or more SS/PBCHblocks (e.g., 4 SS/PBCH blocks, as shown in FIG. 11A). Bursts may betransmitted periodically (e.g., every 2 frames or 20 ms). A burst may berestricted to a half-frame (e.g., a first half-frame having a durationof 5 ms). It will be understood that FIG. 11A is an example, and thatthese parameters (number of SS/PBCH blocks per burst, periodicity ofbursts, position of burst within the frame) may be configured based on,for example: a carrier frequency of a cell in which the SS/PBCH block istransmitted; a numerology or subcarrier spacing of the cell; aconfiguration by the network (e.g., using RRC signaling); or any othersuitable factor. In an example, the UE may assume a subcarrier spacingfor the SS/PBCH block based on the carrier frequency being monitored,unless the radio network configured the UE to assume a differentsubcarrier spacing.

The SS/PBCH block may span one or more OFDM symbols in the time domain(e.g., 4 OFDM symbols, as shown in the example of FIG. 11A) and may spanone or more subcarriers in the frequency domain (e.g., 240 contiguoussubcarriers). The PSS, the SSS, and the PBCH may have a common centerfrequency. The PSS may be transmitted first and may span, for example, 1OFDM symbol and 127 subcarriers. The SSS may be transmitted after thePSS (e.g., two symbols later) and may span 1 OFDM symbol and 127subcarriers. The PBCH may be transmitted after the PSS (e.g., across thenext 3 OFDM symbols) and may span 240 subcarriers.

The location of the SS/PBCH block in the time and frequency domains maynot be known to the UE (e.g., if the UE is searching for the cell). Tofind and select the cell, the UE may monitor a carrier for the PSS. Forexample, the UE may monitor a frequency location within the carrier. Ifthe PSS is not found after a certain duration (e.g., 20 ms), the UE maysearch for the PSS at a different frequency location within the carrier,as indicated by a synchronization raster. If the PSS is found at alocation in the time and frequency domains, the UE may determine, basedon a known structure of the SS/PBCH block, the locations of the SSS andthe PBCH, respectively. The SS/PBCH block may be a cell-defining SSblock (CD-SSB). In an example, a primary cell may be associated with aCD-SSB. The CD-SSB may be located on a synchronization raster. In anexample, a cell selection/search and/or reselection may be based on theCD-SSB.

The SS/PBCH block may be used by the UE to determine one or moreparameters of the cell. For example, the UE may determine a physicalcell identifier (PCI) of the cell based on the sequences of the PSS andthe SSS, respectively. The UE may determine a location of a frameboundary of the cell based on the location of the SS/PBCH block. Forexample, the SS/PBCH block may indicate that it has been transmitted inaccordance with a transmission pattern, wherein a SS/PBCH block in thetransmission pattern is a known distance from the frame boundary.

The PBCH may use a QPSK modulation and may use forward error correction(FEC). The FEC may use polar coding. One or more symbols spanned by thePBCH may carry one or more DMRSs for demodulation of the PBCH. The PBCHmay include an indication of a current system frame number (SFN) of thecell and/or a SS/PBCH block timing index. These parameters mayfacilitate time synchronization of the UE to the base station. The PBCHmay include a master information block (MIB) used to provide the UE withone or more parameters. The MIB may be used by the UE to locateremaining minimum system information (RMSI) associated with the cell.The RMSI may include a System Information Block Type 1 (SIB1). The SIB1may contain information needed by the UE to access the cell. The UE mayuse one or more parameters of the MIB to monitor PDCCH, which may beused to schedule PDSCH. The PDSCH may include the SIB1. The SIB1 may bedecoded using parameters provided in the MIB. The PBCH may indicate anabsence of SIB 1. Based on the PBCH indicating the absence of SIB1, theUE may be pointed to a frequency. The UE may search for an SS/PBCH blockat the frequency to which the UE is pointed.

The UE may assume that one or more SS/PBCH blocks transmitted with asame SS/PBCH block index are quasi co-located (QCLed) (e.g., having thesame/similar Doppler spread, Doppler shift, average gain, average delay,and/or spatial Rx parameters). The UE may not assume QCL for SS/PBCHblock transmissions having different SS/PBCH block indices.

SS/PBCH blocks (e.g., those within a half-frame) may be transmitted inspatial directions (e.g., using different beams that span a coveragearea of the cell). In an example, a first SS/PBCH block may betransmitted in a first spatial direction using a first beam, and asecond SS/PBCH block may be transmitted in a second spatial directionusing a second beam.

In an example, within a frequency span of a carrier, a base station maytransmit a plurality of SS/PBCH blocks. In an example, a first PCI of afirst SS/PBCH block of the plurality of SS/PBCH blocks may be differentfrom a second PCI of a second SS/PBCH block of the plurality of SS/PBCHblocks. The PCIs of SS/PBCH blocks transmitted in different frequencylocations may be different or the same.

The CSI-RS may be transmitted by the base station and used by the UE toacquire channel state information (CSI). The base station may configurethe UE with one or more CSI-RSs for channel estimation or any othersuitable purpose. The base station may configure a UE with one or moreof the same/similar CSI-RSs. The UE may measure the one or more CSI-RSs.The UE may estimate a downlink channel state and/or generate a CSIreport based on the measuring of the one or more downlink CSI-RSs. TheUE may provide the CSI report to the base station. The base station mayuse feedback provided by the UE (e.g., the estimated downlink channelstate) to perform link adaptation.

The base station may semi-statically configure the UE with one or moreCSI-RS resource sets. A CSI-RS resource may be associated with alocation in the time and frequency domains and a periodicity. The basestation may selectively activate and/or deactivate a CSI-RS resource.The base station may indicate to the UE that a CSI-RS resource in theCSI-RS resource set is activated and/or deactivated.

The base station may configure the UE to report CSI measurements. Thebase station may configure the UE to provide CSI reports periodically,aperiodically, or semi-persistently. For periodic CSI reporting, the UEmay be configured with a timing and/or periodicity of a plurality of CSIreports. For aperiodic CSI reporting, the base station may request a CSIreport. For example, the base station may command the UE to measure aconfigured CSI-RS resource and provide a CSI report relating to themeasurements. For semi-persistent CSI reporting, the base station mayconfigure the UE to transmit periodically, and selectively activate ordeactivate the periodic reporting. The base station may configure the UEwith a CSI-RS resource set and CSI reports using RRC signaling.

The CSI-RS configuration may comprise one or more parameters indicating,for example, up to 32 antenna ports. The UE may be configured to employthe same OFDM symbols for a downlink CSI-RS and a control resource set(CORESET) when the downlink CSI-RS and CORESET are spatially QCLed andresource elements associated with the downlink CSI-RS are outside of thephysical resource blocks (PRBs) configured for the CORESET. The UE maybe configured to employ the same OFDM symbols for downlink CSI-RS andSS/PBCH blocks when the downlink CSI-RS and SS/PBCH blocks are spatiallyQCLed and resource elements associated with the downlink CSI-RS areoutside of PRBs configured for the SS/PBCH blocks.

Downlink DMRSs may be transmitted by a base station and used by a UE forchannel estimation. For example, the downlink DMRS may be used forcoherent demodulation of one or more downlink physical channels (e.g.,PDSCH). An NR network may support one or more variable and/orconfigurable DMRS patterns for data demodulation. At least one downlinkDMRS configuration may support a front-loaded DMRS pattern. Afront-loaded DMRS may be mapped over one or more OFDM symbols (e.g., oneor two adjacent OFDM symbols). A base station may semi-staticallyconfigure the UE with a number (e.g. a maximum number) of front-loadedDMRS symbols for PDSCH. A DMRS configuration may support one or moreDMRS ports. For example, for single user-MIMO, a DMRS configuration maysupport up to eight orthogonal downlink DMRS ports per UE. Formultiuser-MIMO, a DMRS configuration may support up to 4 orthogonaldownlink DMRS ports per UE. A radio network may support (e.g., at leastfor CP-OFDM) a common DMRS structure for downlink and uplink, wherein aDMRS location, a DMRS pattern, and/or a scrambling sequence may be thesame or different. The base station may transmit a downlink DMRS and acorresponding PDSCH using the same precoding matrix. The UE may use theone or more downlink DMRSs for coherent demodulation/channel estimationof the PDSCH.

In an example, a transmitter (e.g., a base station) may use a precodermatrices for a part of a transmission bandwidth. For example, thetransmitter may use a first precoder matrix for a first bandwidth and asecond precoder matrix for a second bandwidth. The first precoder matrixand the second precoder matrix may be different based on the firstbandwidth being different from the second bandwidth. The UE may assumethat a same precoding matrix is used across a set of PRBs. The set ofPRBs may be denoted as a precoding resource block group (PRG).

A PDSCH may comprise one or more layers. The UE may assume that at leastone symbol with DMRS is present on a layer of the one or more layers ofthe PDSCH. A higher layer may configure up to 3 DMRSs for the PDSCH.

Downlink PT-RS may be transmitted by a base station and used by a UE forphase-noise compensation. Whether a downlink PT-RS is present or not maydepend on an RRC configuration. The presence and/or pattern of thedownlink PT-RS may be configured on a UE-specific basis using acombination of RRC signaling and/or an association with one or moreparameters employed for other purposes (e.g., modulation and codingscheme (MCS)), which may be indicated by DCI. When configured, a dynamicpresence of a downlink PT-RS may be associated with one or more DCIparameters comprising at least MCS. An NR network may support aplurality of PT-RS densities defined in the time and/or frequencydomains. When present, a frequency domain density may be associated withat least one configuration of a scheduled bandwidth. The UE may assume asame precoding for a DMRS port and a PT-RS port. A number of PT-RS portsmay be fewer than a number of DMRS ports in a scheduled resource.Downlink PT-RS may be confined in the scheduled time/frequency durationfor the UE. Downlink PT-RS may be transmitted on symbols to facilitatephase tracking at the receiver.

The UE may transmit an uplink DMRS to a base station for channelestimation. For example, the base station may use the uplink DMRS forcoherent demodulation of one or more uplink physical channels. Forexample, the UE may transmit an uplink DMRS with a PUSCH and/or a PUCCH.The uplink DM-RS may span a range of frequencies that is similar to arange of frequencies associated with the corresponding physical channel.The base station may configure the UE with one or more uplink DMRSconfigurations. At least one DMRS configuration may support afront-loaded DMRS pattern. The front-loaded DMRS may be mapped over oneor more OFDM symbols (e.g., one or two adjacent OFDM symbols). One ormore uplink DMRSs may be configured to transmit at one or more symbolsof a PUSCH and/or a PUCCH. The base station may semi-staticallyconfigure the UE with a number (e.g. maximum number) of front-loadedDMRS symbols for the PUSCH and/or the PUCCH, which the UE may use toschedule a single-symbol DMRS and/or a double-symbol DMRS. An NR networkmay support (e.g., for cyclic prefix orthogonal frequency divisionmultiplexing (CP-OFDM)) a common DMRS structure for downlink and uplink,wherein a DMRS location, a DMRS pattern, and/or a scrambling sequencefor the DMRS may be the same or different.

A PUSCH may comprise one or more layers, and the UE may transmit atleast one symbol with DMRS present on a layer of the one or more layersof the PUSCH. In an example, a higher layer may configure up to threeDMRSs for the PUSCH.

Uplink PT-RS (which may be used by a base station for phase trackingand/or phase-noise compensation) may or may not be present depending onan RRC configuration of the UE. The presence and/or pattern of uplinkPT-RS may be configured on a UE-specific basis by a combination of RRCsignaling and/or one or more parameters employed for other purposes(e.g., Modulation and Coding Scheme (MCS)), which may be indicated byDCI. When configured, a dynamic presence of uplink PT-RS may beassociated with one or more DCI parameters comprising at least MCS. Aradio network may support a plurality of uplink PT-RS densities definedin time/frequency domain. When present, a frequency domain density maybe associated with at least one configuration of a scheduled bandwidth.The UE may assume a same precoding for a DMRS port and a PT-RS port. Anumber of PT-RS ports may be fewer than a number of DMRS ports in ascheduled resource. For example, uplink PT-RS may be confined in thescheduled time/frequency duration for the UE.

SRS may be transmitted by a UE to a base station for channel stateestimation to support uplink channel dependent scheduling and/or linkadaptation. SRS transmitted by the UE may allow a base station toestimate an uplink channel state at one or more frequencies. A schedulerat the base station may employ the estimated uplink channel state toassign one or more resource blocks for an uplink PUSCH transmission fromthe UE. The base station may semi-statically configure the UE with oneor more SRS resource sets. For an SRS resource set, the base station mayconfigure the UE with one or more SRS resources. An SRS resource setapplicability may be configured by a higher layer (e.g., RRC) parameter.For example, when a higher layer parameter indicates beam management, anSRS resource in a SRS resource set of the one or more SRS resource sets(e.g., with the same/similar time domain behavior, periodic, aperiodic,and/or the like) may be transmitted at a time instant (e.g.,simultaneously). The UE may transmit one or more SRS resources in SRSresource sets. An NR network may support aperiodic, periodic and/orsemi-persistent SRS transmissions. The UE may transmit SRS resourcesbased on one or more trigger types, wherein the one or more triggertypes may comprise higher layer signaling (e.g., RRC) and/or one or moreDCI formats. In an example, at least one DCI format may be employed forthe UE to select at least one of one or more configured SRS resourcesets. An SRS trigger type 0 may refer to an SRS triggered based on ahigher layer signaling. An SRS trigger type 1 may refer to an SRStriggered based on one or more DCI formats. In an example, when PUSCHand SRS are transmitted in a same slot, the UE may be configured totransmit SRS after a transmission of a PUSCH and a corresponding uplinkDMRS.

The base station may semi-statically configure the UE with one or moreSRS configuration parameters indicating at least one of following: a SRSresource configuration identifier; a number of SRS ports; time domainbehavior of an SRS resource configuration (e.g., an indication ofperiodic, semi-persistent, or aperiodic SRS); slot, mini-slot, and/orsubframe level periodicity; offset for a periodic and/or an aperiodicSRS resource; a number of OFDM symbols in an SRS resource; a startingOFDM symbol of an SRS resource; an SRS bandwidth; a frequency hoppingbandwidth; a cyclic shift; and/or an SRS sequence ID.

An antenna port is defined such that the channel over which a symbol onthe antenna port is conveyed can be inferred from the channel over whichanother symbol on the same antenna port is conveyed. If a first symboland a second symbol are transmitted on the same antenna port, thereceiver may infer the channel (e.g., fading gain, multipath delay,and/or the like) for conveying the second symbol on the antenna port,from the channel for conveying the first symbol on the antenna port. Afirst antenna port and a second antenna port may be referred to as quasico-located (QCLed) if one or more large-scale properties of the channelover which a first symbol on the first antenna port is conveyed may beinferred from the channel over which a second symbol on a second antennaport is conveyed. The one or more large-scale properties may comprise atleast one of: a delay spread; a Doppler spread; a Doppler shift; anaverage gain; an average delay; and/or spatial Receiving (Rx)parameters.

Channels that use beamforming require beam management. Beam managementmay comprise beam measurement, beam selection, and beam indication. Abeam may be associated with one or more reference signals. For example,a beam may be identified by one or more beamformed reference signals.The UE may perform downlink beam measurement based on downlink referencesignals (e.g., a channel state information reference signal (CSI-RS))and generate a beam measurement report. The UE may perform the downlinkbeam measurement procedure after an RRC connection is set up with a basestation.

FIG. 11B illustrates an example of channel state information referencesignals (CSI-RSs) that are mapped in the time and frequency domains. Asquare shown in FIG. 11B may span a resource block (RB) within abandwidth of a cell. A base station may transmit one or more RRCmessages comprising CSI-RS resource configuration parameters indicatingone or more CSI-RSs. One or more of the following parameters may beconfigured by higher layer signaling (e.g., RRC and/or MAC signaling)for a CSI-RS resource configuration: a CSI-RS resource configurationidentity, a number of CSI-RS ports, a CSI-RS configuration (e.g., symboland resource element (RE) locations in a subframe), a CSI-RS subframeconfiguration (e.g., subframe location, offset, and periodicity in aradio frame), a CSI-RS power parameter, a CSI-RS sequence parameter, acode division multiplexing (CDM) type parameter, a frequency density, atransmission comb, quasi co-location (QCL) parameters (e.g.,QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist,csi-rs-configZPid, qcl-csi-rs-configNZPid), and/or other radio resourceparameters.

The three beams illustrated in FIG. 11B may be configured for a UE in aUE-specific configuration. Three beams are illustrated in FIG. 11B (beam#1, beam #2, and beam #3), more or fewer beams may be configured. Beam#1 may be allocated with CSI-RS 1101 that may be transmitted in one ormore subcarriers in an RB of a first symbol. Beam #2 may be allocatedwith CSI-RS 1102 that may be transmitted in one or more subcarriers inan RB of a second symbol. Beam #3 may be allocated with CSI-RS 1103 thatmay be transmitted in one or more subcarriers in an RB of a thirdsymbol. By using frequency division multiplexing (FDM), a base stationmay use other subcarriers in a same RB (for example, those that are notused to transmit CSI-RS 1101) to transmit another CSI-RS associated witha beam for another UE. By using time domain multiplexing (TDM), beamsused for the UE may be configured such that beams for the UE use symbolsfrom beams of other UEs.

CSI-RSs such as those illustrated in FIG. 11B (e.g., CSI-RS 1101, 1102,1103) may be transmitted by the base station and used by the UE for oneor more measurements. For example, the UE may measure a reference signalreceived power (RSRP) of configured CSI-RS resources. The base stationmay configure the UE with a reporting configuration and the UE mayreport the RSRP measurements to a network (for example, via one or morebase stations) based on the reporting configuration. In an example, thebase station may determine, based on the reported measurement results,one or more transmission configuration indication (TCI) statescomprising a number of reference signals. In an example, the basestation may indicate one or more TCI states to the UE (e.g., via RRCsignaling, a MAC CE, and/or a DCI). The UE may receive a downlinktransmission with a receive (Rx) beam determined based on the one ormore TCI states. In an example, the UE may or may not have a capabilityof beam correspondence. If the UE has the capability of beamcorrespondence, the UE may determine a spatial domain filter of atransmit (Tx) beam based on a spatial domain filter of the correspondingRx beam. If the UE does not have the capability of beam correspondence,the UE may perform an uplink beam selection procedure to determine thespatial domain filter of the Tx beam. The UE may perform the uplink beamselection procedure based on one or more sounding reference signal (SRS)resources configured to the UE by the base station. The base station mayselect and indicate uplink beams for the UE based on measurements of theone or more SRS resources transmitted by the UE.

In a beam management procedure, a UE may assess (e.g., measure) achannel quality of one or more beam pair links, a beam pair linkcomprising a transmitting beam transmitted by a base station and areceiving beam received by the UE. Based on the assessment, the UE maytransmit a beam measurement report indicating one or more beam pairquality parameters comprising, e.g., one or more beam identifications(e.g., a beam index, a reference signal index, or the like), RSRP, aprecoding matrix indicator (PMI), a channel quality indicator (CQI),and/or a rank indicator (RI).

FIG. 12A illustrates examples of three downlink beam managementprocedures: P1, P2, and P3. Procedure P1 may enable a UE measurement ontransmit (Tx) beams of a transmission reception point (TRP) (or multipleTRPs), e.g., to support a selection of one or more base station Tx beamsand/or UE Rx beams (shown as ovals in the top row and bottom row,respectively, of P1). Beamforming at a TRP may comprise a Tx beam sweepfor a set of beams (shown, in the top rows of P1 and P2, as ovalsrotated in a counter-clockwise direction indicated by the dashed arrow).Beamforming at a UE may comprise an Rx beam sweep for a set of beams(shown, in the bottom rows of P1 and P3, as ovals rotated in a clockwisedirection indicated by the dashed arrow). Procedure P2 may be used toenable a UE measurement on Tx beams of a TRP (shown, in the top row ofP2, as ovals rotated in a counter-clockwise direction indicated by thedashed arrow). The UE and/or the base station may perform procedure P2using a smaller set of beams than is used in procedure P1, or usingnarrower beams than the beams used in procedure P1. This may be referredto as beam refinement. The UE may perform procedure P3 for Rx beamdetermination by using the same Tx beam at the base station and sweepingan Rx beam at the UE.

FIG. 12B illustrates examples of three uplink beam managementprocedures: U1, U2, and U3. Procedure U1 may be used to enable a basestation to perform a measurement on Tx beams of a UE, e.g., to support aselection of one or more UE Tx beams and/or base station Rx beams (shownas ovals in the top row and bottom row, respectively, of U1).

Beamforming at the UE may include, e.g., a Tx beam sweep from a set ofbeams (shown in the bottom rows of U1 and U3 as ovals rotated in aclockwise direction indicated by the dashed arrow). Beamforming at thebase station may include, e.g., an Rx beam sweep from a set of beams(shown, in the top rows of U1 and U2, as ovals rotated in acounter-clockwise direction indicated by the dashed arrow). Procedure U2may be used to enable the base station to adjust its Rx beam when the UEuses a fixed Tx beam. The UE and/or the base station may performprocedure U2 using a smaller set of beams than is used in procedure P1,or using narrower beams than the beams used in procedure P1. This may bereferred to as beam refinement The UE may perform procedure U3 to adjustits Tx beam when the base station uses a fixed Rx beam.

A UE may initiate a beam failure recovery (BFR) procedure based ondetecting a beam failure. The UE may transmit a BFR request (e.g., apreamble, a UCI, an SR, a MAC CE, and/or the like) based on theinitiating of the BFR procedure. The UE may detect the beam failurebased on a determination that a quality of beam pair link(s) of anassociated control channel is unsatisfactory (e.g., having an error ratehigher than an error rate threshold, a received signal power lower thana received signal power threshold, an expiration of a timer, and/or thelike).

The UE may measure a quality of a beam pair link using one or morereference signals (RSs) comprising one or more SS/PBCH blocks, one ormore CSI-RS resources, and/or one or more demodulation reference signals(DMRSs). A quality of the beam pair link may be based on one or more ofa block error rate (BLER), an RSRP value, a signal to interference plusnoise ratio (SINR) value, a reference signal received quality (RSRQ)value, and/or a CSI value measured on RS resources. The base station mayindicate that an RS resource is quasi co-located (QCLed) with one ormore DM-RSs of a channel (e.g., a control channel, a shared datachannel, and/or the like). The RS resource and the one or more DMRSs ofthe channel may be QCLed when the channel characteristics (e.g., Dopplershift, Doppler spread, average delay, delay spread, spatial Rxparameter, fading, and/or the like) from a transmission via the RSresource to the UE are similar or the same as the channelcharacteristics from a transmission via the channel to the UE.

A network (e.g., a gNB and/or an ng-eNB of a network) and/or the UE mayinitiate a random access procedure. A UE in an RRC_IDLE state and/or anRRC_INACTIVE state may initiate the random access procedure to request aconnection setup to a network. The UE may initiate the random accessprocedure from an RRC_CONNECTED state. The UE may initiate the randomaccess procedure to request uplink resources (e.g., for uplinktransmission of an SR when there is no PUCCH resource available) and/oracquire uplink timing (e.g., when uplink synchronization status isnon-synchronized). The UE may initiate the random access procedure torequest one or more system information blocks (SIBs) (e.g., other systeminformation such as SIB2, SIB3, and/or the like). The UE may initiatethe random access procedure for a beam failure recovery request. Anetwork may initiate a random access procedure for a handover and/or forestablishing time alignment for an SCell addition.

FIG. 13A illustrates a four-step contention-based random accessprocedure. Prior to initiation of the procedure, a base station maytransmit a configuration message 1310 to the UE. The procedureillustrated in FIG. 13A comprises transmission of four messages: a Msg 11311, a Msg 2 1312, a Msg 3 1313, and a Msg 4 1314. The Msg 1 1311 mayinclude and/or be referred to as a preamble (or a random accesspreamble). The Msg 2 1312 may include and/or be referred to as a randomaccess response (RAR).

The configuration message 1310 may be transmitted, for example, usingone or more RRC messages. The one or more RRC messages may indicate oneor more random access channel (RACH) parameters to the UE. The one ormore RACH parameters may comprise at least one of following: generalparameters for one or more random access procedures (e.g.,RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon);and/or dedicated parameters (e.g., RACH-configDedicated). The basestation may broadcast or multicast the one or more RRC messages to oneor more UEs. The one or more RRC messages may be UE-specific (e.g.,dedicated RRC messages transmitted to a UE in an RRC_CONNECTED stateand/or in an RRC_INACTIVE state). The UE may determine, based on the oneor more RACH parameters, a time-frequency resource and/or an uplinktransmit power for transmission of the Msg 1 1311 and/or the Msg 3 1313.Based on the one or more RACH parameters, the UE may determine areception timing and a downlink channel for receiving the Msg 2 1312 andthe Msg 4 1314.

The one or more RACH parameters provided in the configuration message1310 may indicate one or more Physical RACH (PRACH) occasions availablefor transmission of the Msg 1 1311. The one or more PRACH occasions maybe predefined. The one or more RACH parameters may indicate one or moreavailable sets of one or more PRACH occasions (e.g., prach-ConfigIndex).The one or more RACH parameters may indicate an association between (a)one or more PRACH occasions and (b) one or more reference signals. Theone or more RACH parameters may indicate an association between (a) oneor more preambles and (b) one or more reference signals. The one or morereference signals may be SS/PBCH blocks and/or CSI-RSs. For example, theone or more RACH parameters may indicate a number of SS/PBCH blocksmapped to a PRACH occasion and/or a number of preambles mapped to aSS/PBCH blocks.

The one or more RACH parameters provided in the configuration message1310 may be used to determine an uplink transmit power of Msg 1 1311and/or Msg 3 1313. For example, the one or more RACH parameters mayindicate a reference power for a preamble transmission (e.g., a receivedtarget power and/or an initial power of the preamble transmission).There may be one or more power offsets indicated by the one or more RACHparameters. For example, the one or more RACH parameters may indicate: apower ramping step; a power offset between SSB and CSI-RS; a poweroffset between transmissions of the Msg 1 1311 and the Msg 3 1313;and/or a power offset value between preamble groups. The one or moreRACH parameters may indicate one or more thresholds based on which theUE may determine at least one reference signal (e.g., an SSB and/orCSI-RS) and/or an uplink carrier (e.g., a normal uplink (NUL) carrierand/or a supplemental uplink (SUL) carrier).

The Msg 1 1311 may include one or more preamble transmissions (e.g., apreamble transmission and one or more preamble retransmissions). An RRCmessage may be used to configure one or more preamble groups (e.g.,group A and/or group B). A preamble group may comprise one or morepreambles. The UE may determine the preamble group based on a pathlossmeasurement and/or a size of the Msg 3 1313. The UE may measure an RSRPof one or more reference signals (e.g., SSBs and/or CSI-RSs) anddetermine at least one reference signal having an RSRP above an RSRPthreshold (e.g., rsrp-ThresholdSSB and/or rsrp-ThresholdCSI-RS). The UEmay select at least one preamble associated with the one or morereference signals and/or a selected preamble group, for example, if theassociation between the one or more preambles and the at least onereference signal is configured by an RRC message.

The UE may determine the preamble based on the one or more RACHparameters provided in the configuration message 1310. For example, theUE may determine the preamble based on a pathloss measurement, an RSRPmeasurement, and/or a size of the Msg 3 1313. As another example, theone or more RACH parameters may indicate: a preamble format; a maximumnumber of preamble transmissions; and/or one or more thresholds fordetermining one or more preamble groups (e.g., group A and group B). Abase station may use the one or more RACH parameters to configure the UEwith an association between one or more preambles and one or morereference signals (e.g., SSBs and/or CSI-RSs). If the association isconfigured, the UE may determine the preamble to include in Msg 1 1311based on the association. The Msg 1 1311 may be transmitted to the basestation via one or more PRACH occasions. The UE may use one or morereference signals (e.g., SSBs and/or CSI-RSs) for selection of thepreamble and for determining of the PRACH occasion. One or more RACHparameters (e.g., ra-ssb-OccasionMskIndex and/or ra-OccasionList) mayindicate an association between the PRACH occasions and the one or morereference signals.

The UE may perform a preamble retransmission if no response is receivedfollowing a preamble transmission. The UE may increase an uplinktransmit power for the preamble retransmission. The UE may select aninitial preamble transmit power based on a pathloss measurement and/or atarget received preamble power configured by the network. The UE maydetermine to retransmit a preamble and may ramp up the uplink transmitpower. The UE may receive one or more RACH parameters (e.g.,PREAMBLE_POWER_RAMPING_STEP) indicating a ramping step for the preambleretransmission. The ramping step may be an amount of incrementalincrease in uplink transmit power for a retransmission. The UE may rampup the uplink transmit power if the UE determines a reference signal(e.g., SSB and/or CSI-RS) that is the same as a previous preambletransmission. The UE may count a number of preamble transmissions and/orretransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). The UE maydetermine that a random access procedure completed unsuccessfully, forexample, if the number of preamble transmissions exceeds a thresholdconfigured by the one or more RACH parameters (e.g., preambleTransMax).

The Msg 2 1312 received by the UE may include an RAR. In some scenarios,the Msg 2 1312 may include multiple RARs corresponding to multiple UEs.The Msg 2 1312 may be received after or in response to the transmittingof the Msg 1 1311. The Msg 2 1312 may be scheduled on the DL-SCH andindicated on a PDCCH using a random access RNTI (RA-RNTI). The Msg 21312 may indicate that the Msg 1 1311 was received by the base station.The Msg 2 1312 may include a time-alignment command that may be used bythe UE to adjust the UE's transmission timing, a scheduling grant fortransmission of the Msg 3 1313, and/or a Temporary Cell RNTI (TC-RNTI).After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the Msg 2 1312. The UE maydetermine when to start the time window based on a PRACH occasion thatthe UE uses to transmit the preamble. For example, the UE may start thetime window one or more symbols after a last symbol of the preamble(e.g., at a first PDCCH occasion from an end of a preambletransmission). The one or more symbols may be determined based on anumerology. The PDCCH may be in a common search space (e.g., aType1-PDCCH common search space) configured by an RRC message. The UEmay identify the RAR based on a Radio Network Temporary Identifier(RNTI). RNTIs may be used depending on one or more events initiating therandom access procedure. The UE may use random access RNTI (RA-RNTI).The RA-RNTI may be associated with PRACH occasions in which the UEtransmits a preamble. For example, the UE may determine the RA-RNTIbased on: an OFDM symbol index; a slot index; a frequency domain index;and/or a UL carrier indicator of the PRACH occasions. An example ofRA-RNTI may be as follows:

RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

where s_id may be an index of a first OFDM symbol of the PRACH occasion(e.g., 0≤s_id<14), t_id may be an index of a first slot of the PRACHoccasion in a system frame (e.g., 0≤t_id<80), fid may be an index of thePRACH occasion in the frequency domain (e.g., 0≤f_id<8), andul_carrier_id may be a UL carrier used for a preamble transmission(e.g., 0 for an NUL carrier, and 1 for an SUL carrier).

The UE may transmit the Msg 3 1313 in response to a successful receptionof the Msg 2 1312 (e.g., using resources identified in the Msg 2 1312).The Msg 3 1313 may be used for contention resolution in, for example,the contention-based random access procedure illustrated in FIG. 13A. Insome scenarios, a plurality of UEs may transmit a same preamble to abase station and the base station may provide an RAR that corresponds toa UE. Collisions may occur if the plurality of UEs interpret the RAR ascorresponding to themselves. Contention resolution (e.g., using the Msg3 1313 and the Msg 4 1314) may be used to increase the likelihood thatthe UE does not incorrectly use an identity of another the UE. Toperform contention resolution, the UE may include a device identifier inthe Msg 3 1313 (e.g., a C-RNTI if assigned, a TC-RNTI included in theMsg 2 1312, and/or any other suitable identifier).

The Msg 4 1314 may be received after or in response to the transmittingof the Msg 3 1313. If a C-RNTI was included in the Msg 3 1313, the basestation will address the UE on the PDCCH using the C-RNTI. If the UE'sunique C-RNTI is detected on the PDCCH, the random access procedure isdetermined to be successfully completed. If a TC-RNTI is included in theMsg 3 1313 (e.g., if the UE is in an RRC_IDLE state or not otherwiseconnected to the base station), Msg 4 1314 will be received using aDL-SCH associated with the TC-RNTI. If a MAC PDU is successfully decodedand a MAC PDU comprises the UE contention resolution identity MAC CEthat matches or otherwise corresponds with the CCCH SDU sent (e.g.,transmitted) in Msg 3 1313, the UE may determine that the contentionresolution is successful and/or the UE may determine that the randomaccess procedure is successfully completed.

The UE may be configured with a supplementary uplink (SUL) carrier and anormal uplink (NUL) carrier. An initial access (e.g., random accessprocedure) may be supported in an uplink carrier. For example, a basestation may configure the UE with two separate RACH configurations: onefor an SUL carrier and the other for an NUL carrier. For random accessin a cell configured with an SUL carrier, the network may indicate whichcarrier to use (NUL or SUL). The UE may determine the SUL carrier, forexample, if a measured quality of one or more reference signals is lowerthan a broadcast threshold. Uplink transmissions of the random accessprocedure (e.g., the Msg 1 1311 and/or the Msg 3 1313) may remain on theselected carrier. The UE may switch an uplink carrier during the randomaccess procedure (e.g., between the Msg 1 1311 and the Msg 3 1313) inone or more cases. For example, the UE may determine and/or switch anuplink carrier for the Msg 1 1311 and/or the Msg 3 1313 based on achannel clear assessment (e.g., a listen-before-talk).

FIG. 13B illustrates a two-step contention-free random access procedure.Similar to the four-step contention-based random access procedureillustrated in FIG. 13A, a base station may, prior to initiation of theprocedure, transmit a configuration message 1320 to the UE. Theconfiguration message 1320 may be analogous in some respects to theconfiguration message 1310. The procedure illustrated in FIG. 13Bcomprises transmission of two messages: a Msg 1 1321 and a Msg 2 1322.The Msg 1 1321 and the Msg 2 1322 may be analogous in some respects tothe Msg 1 1311 and a Msg 2 1312 illustrated in FIG. 13A, respectively.As will be understood from FIGS. 13A and 13B, the contention-free randomaccess procedure may not include messages analogous to the Msg 3 1313and/or the Msg 4 1314.

The contention-free random access procedure illustrated in FIG. 13B maybe initiated for a beam failure recovery, other SI request, SCelladdition, and/or handover. For example, a base station may indicate orassign to the UE the preamble to be used for the Msg 1 1321. The UE mayreceive, from the base station via PDCCH and/or RRC, an indication of apreamble (e.g., ra-PreambleIndex).

After transmitting a preamble, the UE may start a time window (e.g.,ra-ResponseWindow) to monitor a PDCCH for the RAR. In the event of abeam failure recovery request, the base station may configure the UEwith a separate time window and/or a separate PDCCH in a search spaceindicated by an RRC message (e.g., recoverySearchSpaceId). The UE maymonitor for a PDCCH transmission addressed to a Cell RNTI (C-RNTI) onthe search space. In the contention-free random access procedureillustrated in FIG. 13B, the UE may determine that a random accessprocedure successfully completes after or in response to transmission ofMsg 1 1321 and reception of a corresponding Msg 2 1322. The UE maydetermine that a random access procedure successfully completes, forexample, if a PDCCH transmission is addressed to a C-RNTI. The UE maydetermine that a random access procedure successfully completes, forexample, if the UE receives an RAR comprising a preamble identifiercorresponding to a preamble transmitted by the UE and/or the RARcomprises a MAC sub-PDU with the preamble identifier. The UE maydetermine the response as an indication of an acknowledgement for an SIrequest.

FIG. 13C illustrates another two-step random access procedure. Similarto the random access procedures illustrated in FIGS. 13A and 13B, a basestation may, prior to initiation of the procedure, transmit aconfiguration message 1330 to the UE. The configuration message 1330 maybe analogous in some respects to the configuration message 1310 and/orthe configuration message 1320. The procedure illustrated in FIG. 13Ccomprises transmission of two messages: a Msg A 1331 and a Msg B 1332.

Msg A 1320 may be transmitted in an uplink transmission by the UE. Msg A1320 may comprise one or more transmissions of a preamble 1341 and/orone or more transmissions of a transport block 1342. The transport block1342 may comprise contents that are similar and/or equivalent to thecontents of the Msg 3 1313 illustrated in FIG. 13A. The transport block1342 may comprise UCI (e.g., an SR, a HARQ ACK/NACK, and/or the like).The UE may receive the Msg B 1350 after or in response to transmittingthe Msg A 1320. The Msg B 1350 may comprise contents that are similarand/or equivalent to the contents of the Msg 2 1312 (e.g., an RAR)illustrated in FIGS. 13A and 13B and/or the Msg 4 1314 illustrated inFIG. 13A.

The UE may initiate the two-step random access procedure in FIG. 13C forlicensed spectrum and/or unlicensed spectrum. The UE may determine,based on one or more factors, whether to initiate the two-step randomaccess procedure. The one or more factors may be: a radio accesstechnology in use (e.g., LTE, NR, and/or the like); whether the UE hasvalid TA or not; a cell size; the UE's RRC state; a type of spectrum(e.g., licensed vs. unlicensed); and/or any other suitable factors.

The UE may determine, based on two-step RACH parameters included in theconfiguration message 1330, a radio resource and/or an uplink transmitpower for the preamble 1341 and/or the transport block 1342 included inthe Msg A 1331. The RACH parameters may indicate a modulation and codingschemes (MCS), a time-frequency resource, and/or a power control for thepreamble 1341 and/or the transport block 1342. A time-frequency resourcefor transmission of the preamble 1341 (e.g., a PRACH) and atime-frequency resource for transmission of the transport block 1342(e.g., a PUSCH) may be multiplexed using FDM, TDM, and/or CDM. The RACHparameters may enable the UE to determine a reception timing and adownlink channel for monitoring for and/or receiving Msg B 1350.

The transport block 1342 may comprise data (e.g., delay-sensitive data),an identifier of the UE, security information, and/or device information(e.g., an International Mobile Subscriber Identity (IMSI)). The basestation may transmit the Msg B 1332 as a response to the Msg A 1331. TheMsg B 1332 may comprise at least one of following: a preambleidentifier; a timing advance command; a power control command; an uplinkgrant (e.g., a radio resource assignment and/or an MCS); a UE identifierfor contention resolution; and/or an RNTI (e.g., a C-RNTI or a TC-RNTI).The UE may determine that the two-step random access procedure issuccessfully completed if: a preamble identifier in the Msg B 1332 ismatched to a preamble transmitted by the UE; and/or the identifier ofthe UE in Msg B 1332 is matched to the identifier of the UE in the Msg A1331 (e.g., the transport block 1342).

A UE and a base station may exchange control signaling. The controlsignaling may be referred to as L1/L2 control signaling and mayoriginate from the PHY layer (e.g., layer 1) and/or the MAC layer (e.g.,layer 2). The control signaling may comprise downlink control signalingtransmitted from the base station to the UE and/or uplink controlsignaling transmitted from the UE to the base station.

The downlink control signaling may comprise: a downlink schedulingassignment; an uplink scheduling grant indicating uplink radio resourcesand/or a transport format; a slot format information; a preemptionindication; a power control command; and/or any other suitablesignaling. The UE may receive the downlink control signaling in apayload transmitted by the base station on a physical downlink controlchannel (PDCCH). The payload transmitted on the PDCCH may be referred toas downlink control information (DCI). In some scenarios, the PDCCH maybe a group common PDCCH (GC-PDCCH) that is common to a group of UEs.

A base station may attach one or more cyclic redundancy check (CRC)parity bits to a DCI in order to facilitate detection of transmissionerrors. When the DCI is intended for a UE (or a group of the UEs), thebase station may scramble the CRC parity bits with an identifier of theUE (or an identifier of the group of the UEs). Scrambling the CRC paritybits with the identifier may comprise Modulo-2 addition (or an exclusiveOR operation) of the identifier value and the CRC parity bits. Theidentifier may comprise a 16-bit value of a radio network temporaryidentifier (RNTI).

DCIs may be used for different purposes. A purpose may be indicated bythe type of RNTI used to scramble the CRC parity bits. For example, aDCI having CRC parity bits scrambled with a paging RNTI (P-RNTI) mayindicate paging information and/or a system information changenotification. The P-RNTI may be predefined as “FFFE” in hexadecimal. ADCI having CRC parity bits scrambled with a system information RNTI(SI-RNTI) may indicate a broadcast transmission of the systeminformation. The SI-RNTI may be predefined as “FFFF” in hexadecimal. ADCI having CRC parity bits scrambled with a random access RNTI (RA-RNTI)may indicate a random access response (RAR). A DCI having CRC paritybits scrambled with a cell RNTI (C-RNTI) may indicate a dynamicallyscheduled unicast transmission and/or a triggering of PDCCH-orderedrandom access. A DCI having CRC parity bits scrambled with a temporarycell RNTI (TC-RNTI) may indicate a contention resolution (e.g., a Msg 3analogous to the Msg 3 1313 illustrated in FIG. 13A). Other RNTIsconfigured to the UE by a base station may comprise a ConfiguredScheduling RNTI (CS-RNTI), a Transmit Power Control-PUCCH RNTI(TPC-PUCCH-RNTI), a Transmit Power Control-PUSCH RNTI (TPC-PUSCH-RNTI),a Transmit Power Control-SRS RNTI (TPC-SRS-RNTI), an Interruption RNTI(INT-RNTI), a Slot Format Indication RNTI (SFI-RNTI), a Semi-PersistentCSI RNTI (SP-CSI-RNTI), a Modulation and Coding Scheme Cell RNTI(MCS-C-RNTI), and/or the like.

Depending on the purpose and/or content of a DCI, the base station maytransmit the DCIs with one or more DCI formats. For example, DCI format0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may bea fallback DCI format (e.g., with compact DCI payloads). DCI format 0_1may be used for scheduling of PUSCH in a cell (e.g., with more DCIpayloads than DCI format 0_0). DCI format 1_0 may be used for schedulingof PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g.,with compact DCI payloads). DCI format 1_1 may be used for scheduling ofPDSCH in a cell (e.g., with more DCI payloads than DCI format 1_0). DCIformat 2_0 may be used for providing a slot format indication to a groupof UEs. DCI format 2_1 may be used for notifying a group of UEs of aphysical resource block and/or OFDM symbol where the UE may assume notransmission is intended to the UE. DCI format 2_2 may be used fortransmission of a transmit power control (TPC) command for PUCCH orPUSCH. DCI format 2_3 may be used for transmission of a group of TPCcommands for SRS transmissions by one or more UEs. DCI format(s) for newfunctions may be defined in future releases. DCI formats may havedifferent DCI sizes, or may share the same DCI size.

After scrambling a DCI with a RNTI, the base station may process the DCIwith channel coding (e.g., polar coding), rate matching, scramblingand/or QPSK modulation. A base station may map the coded and modulatedDCI on resource elements used and/or configured for a PDCCH. Based on apayload size of the DCI and/or a coverage of the base station, the basestation may transmit the DCI via a PDCCH occupying a number ofcontiguous control channel elements (CCEs). The number of the contiguousCCEs (referred to as aggregation level) may be 1, 2, 4, 8, 16, and/orany other suitable number. A CCE may comprise a number (e.g., 6) ofresource-element groups (REGs). A REG may comprise a resource block inan OFDM symbol. The mapping of the coded and modulated DCI on theresource elements may be based on mapping of CCEs and REGs (e.g.,CCE-to-REG mapping).

FIG. 14A illustrates an example of CORESET configurations for abandwidth part. The base station may transmit a DCI via a PDCCH on oneor more control resource sets (CORESETs). A CORESET may comprise atime-frequency resource in which the UE tries to decode a DCI using oneor more search spaces. The base station may configure a size and alocation of the CORESET in the time-frequency domain. In the example ofFIG. 14A, a first CORESET 1401 and a second CORESET 1402 occur at thefirst symbol in a slot. The first CORESET 1401 overlaps with the secondCORESET 1402 in the frequency domain. A third CORESET 1403 occurs at athird symbol in the slot. A fourth CORESET 1404 occurs at the seventhsymbol in the slot. CORESETs may have a different number of resourceblocks in frequency domain.

FIG. 14B illustrates an example of a CCE-to-REG mapping for DCItransmission on a CORESET and PDCCH processing. The CCE-to-REG mappingmay be an interleaved mapping (e.g., for the purpose of providingfrequency diversity) or a non-interleaved mapping (e.g., for thepurposes of facilitating interference coordination and/orfrequency-selective transmission of control channels). The base stationmay perform different or same CCE-to-REG mapping on different CORESETs.A CORESET may be associated with a CCE-to-REG mapping by RRCconfiguration. A CORESET may be configured with an antenna port quasico-location (QCL) parameter. The antenna port QCL parameter may indicateQCL information of a demodulation reference signal (DMRS) for PDCCHreception in the CORESET.

The base station may transmit, to the UE, RRC messages comprisingconfiguration parameters of one or more CORESETs and one or more searchspace sets. The configuration parameters may indicate an associationbetween a search space set and a CORESET. A search space set maycomprise a set of PDCCH candidates formed by CCEs at a given aggregationlevel. The configuration parameters may indicate: a number of PDCCHcandidates to be monitored per aggregation level; a PDCCH monitoringperiodicity and a PDCCH monitoring pattern; one or more DCI formats tobe monitored by the UE; and/or whether a search space set is a commonsearch space set or a UE-specific search space set. A set of CCEs in thecommon search space set may be predefined and known to the UE. A set ofCCEs in the UE-specific search space set may be configured based on theUE's identity (e.g., C-RNTI).

As shown in FIG. 14B, the UE may determine a time-frequency resource fora CORESET based on RRC messages. The UE may determine a CCE-to-REGmapping (e.g., interleaved or non-interleaved, and/or mappingparameters) for the CORESET based on configuration parameters of theCORESET. The UE may determine a number (e.g., at most 10) of searchspace sets configured on the CORESET based on the RRC messages. The UEmay monitor a set of PDCCH candidates according to configurationparameters of a search space set. The UE may monitor a set of PDCCHcandidates in one or more CORESETs for detecting one or more DCIs.Monitoring may comprise decoding one or more PDCCH candidates of the setof the PDCCH candidates according to the monitored DCI formats.Monitoring may comprise decoding a DCI content of one or more PDCCHcandidates with possible (or configured) PDCCH locations, possible (orconfigured) PDCCH formats (e.g., number of CCEs, number of PDCCHcandidates in common search spaces, and/or number of PDCCH candidates inthe UE-specific search spaces) and possible (or configured) DCI formats.The decoding may be referred to as blind decoding. The UE may determinea DCI as valid for the UE, in response to CRC checking (e.g., scrambledbits for CRC parity bits of the DCI matching a RNTI value). The UE mayprocess information contained in the DCI (e.g., a scheduling assignment,an uplink grant, power control, a slot format indication, a downlinkpreemption, and/or the like).

The UE may transmit uplink control signaling (e.g., uplink controlinformation (UCI)) to a base station. The uplink control signaling maycomprise hybrid automatic repeat request (HARQ) acknowledgements forreceived DL-SCH transport blocks. The UE may transmit the HARQacknowledgements after receiving a DL-SCH transport block. Uplinkcontrol signaling may comprise channel state information (CSI)indicating channel quality of a physical downlink channel. The UE maytransmit the CSI to the base station. The base station, based on thereceived CSI, may determine transmission format parameters (e.g.,comprising multi-antenna and beamforming schemes) for a downlinktransmission. Uplink control signaling may comprise scheduling requests(SR). The UE may transmit an SR indicating that uplink data is availablefor transmission to the base station. The UE may transmit a UCI (e.g.,HARQ acknowledgements (HARQ-ACK), CSI report, SR, and the like) via aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUSCH). The UE may transmit the uplink control signaling via aPUCCH using one of several PUCCH formats.

There may be five PUCCH formats and the UE may determine a PUCCH formatbased on a size of the UCI (e.g., a number of uplink symbols of UCItransmission and a number of UCI bits). PUCCH format 0 may have a lengthof one or two OFDM symbols and may include two or fewer bits. The UE maytransmit UCI in a PUCCH resource using PUCCH format 0 if thetransmission is over one or two symbols and the number of HARQ-ACKinformation bits with positive or negative SR (HARQ-ACK/SR bits) is oneor two. PUCCH format 1 may occupy a number between four and fourteenOFDM symbols and may include two or fewer bits. The UE may use PUCCHformat 1 if the transmission is four or more symbols and the number ofHARQ-ACK/SR bits is one or two. PUCCH format 2 may occupy one or twoOFDM symbols and may include more than two bits. The UE may use PUCCHformat 2 if the transmission is over one or two symbols and the numberof UCI bits is two or more. PUCCH format 3 may occupy a number betweenfour and fourteen OFDM symbols and may include more than two bits. TheUE may use PUCCH format 3 if the transmission is four or more symbols,the number of UCI bits is two or more and PUCCH resource does notinclude an orthogonal cover code. PUCCH format 4 may occupy a numberbetween four and fourteen OFDM symbols and may include more than twobits. The UE may use PUCCH format 4 if the transmission is four or moresymbols, the number of UCI bits is two or more and the PUCCH resourceincludes an orthogonal cover code.

The base station may transmit configuration parameters to the UE for aplurality of PUCCH resource sets using, for example, an RRC message. Theplurality of PUCCH resource sets (e.g., up to four sets) may beconfigured on an uplink BWP of a cell. A PUCCH resource set may beconfigured with a PUCCH resource set index, a plurality of PUCCHresources with a PUCCH resource being identified by a PUCCH resourceidentifier (e.g., pucch-Resourceid), and/or a number (e.g. a maximumnumber) of UCI information bits the UE may transmit using one of theplurality of PUCCH resources in the PUCCH resource set. When configuredwith a plurality of PUCCH resource sets, the UE may select one of theplurality of PUCCH resource sets based on a total bit length of the UCIinformation bits (e.g., HARQ-ACK, SR, and/or CSI). If the total bitlength of UCI information bits is two or fewer, the UE may select afirst PUCCH resource set having a PUCCH resource set index equal to “0”.If the total bit length of UCI information bits is greater than two andless than or equal to a first configured value, the UE may select asecond PUCCH resource set having a PUCCH resource set index equal to“1”. If the total bit length of UCI information bits is greater than thefirst configured value and less than or equal to a second configuredvalue, the UE may select a third PUCCH resource set having a PUCCHresource set index equal to “2”. If the total bit length of UCIinformation bits is greater than the second configured value and lessthan or equal to a third value (e.g., 1406), the UE may select a fourthPUCCH resource set having a PUCCH resource set index equal to “3”.

After determining a PUCCH resource set from a plurality of PUCCHresource sets, the UE may determine a PUCCH resource from the PUCCHresource set for UCI (HARQ-ACK, CSI, and/or SR) transmission. The UE maydetermine the PUCCH resource based on a PUCCH resource indicator in aDCI (e.g., with a DCI format 1_0 or DCI for 1_1) received on a PDCCH. Athree-bit PUCCH resource indicator in the DCI may indicate one of eightPUCCH resources in the PUCCH resource set. Based on the PUCCH resourceindicator, the UE may transmit the UCI (HARQ-ACK, CSI and/or SR) using aPUCCH resource indicated by the PUCCH resource indicator in the DCI.

FIG. 15 illustrates an example of a wireless device 1502 incommunication with a base station 1504 in accordance with embodiments ofthe present disclosure. The wireless device 1502 and base station 1504may be part of a mobile communication network, such as the mobilecommunication network 100 illustrated in FIG. 1A, the mobilecommunication network 150 illustrated in FIG. 1B, or any othercommunication network. Only one wireless device 1502 and one basestation 1504 are illustrated in FIG. 15, but it will be understood thata mobile communication network may include more than one UE and/or morethan one base station, with the same or similar configuration as thoseshown in FIG. 15.

The base station 1504 may connect the wireless device 1502 to a corenetwork (not shown) through radio communications over the air interface(or radio interface) 1506. The communication direction from the basestation 1504 to the wireless device 1502 over the air interface 1506 isknown as the downlink, and the communication direction from the wirelessdevice 1502 to the base station 1504 over the air interface is known asthe uplink. Downlink transmissions may be separated from uplinktransmissions using FDD, TDD, and/or some combination of the twoduplexing techniques.

In the downlink, data to be sent to the wireless device 1502 from thebase station 1504 may be provided to the processing system 1508 of thebase station 1504. The data may be provided to the processing system1508 by, for example, a core network. In the uplink, data to be sent tothe base station 1504 from the wireless device 1502 may be provided tothe processing system 1518 of the wireless device 1502. The processingsystem 1508 and the processing system 1518 may implement layer 3 andlayer 2 OSI functionality to process the data for transmission. Layer 2may include an SDAP layer, a PDCP layer, an RLC layer, and a MAC layer,for example, with respect to FIG. 2A, FIG. 2B, FIG. 3, and FIG. 4A.Layer 3 may include an RRC layer as with respect to FIG. 2B.

After being processed by processing system 1508, the data to be sent tothe wireless device 1502 may be provided to a transmission processingsystem 1510 of base station 1504. Similarly, after being processed bythe processing system 1518, the data to be sent to base station 1504 maybe provided to a transmission processing system 1520 of the wirelessdevice 1502. The transmission processing system 1510 and thetransmission processing system 1520 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3, and FIG. 4A. For transmit processing, the PHY layer mayperform, for example, forward error correction coding of transportchannels, interleaving, rate matching, mapping of transport channels tophysical channels, modulation of physical channel, multiple-inputmultiple-output (MIMO) or multi-antenna processing, and/or the like.

At the base station 1504, a reception processing system 1512 may receivethe uplink transmission from the wireless device 1502. At the wirelessdevice 1502, a reception processing system 1522 may receive the downlinktransmission from base station 1504. The reception processing system1512 and the reception processing system 1522 may implement layer 1 OSIfunctionality. Layer 1 may include a PHY layer with respect to FIG. 2A,FIG. 2B, FIG. 3, and FIG. 4A. For receive processing, the PHY layer mayperform, for example, error detection, forward error correctiondecoding, deinterleaving, demapping of transport channels to physicalchannels, demodulation of physical channels, MIMO or multi-antennaprocessing, and/or the like.

As shown in FIG. 15, a wireless device 1502 and the base station 1504may include multiple antennas. The multiple antennas may be used toperform one or more MIMO or multi-antenna techniques, such as spatialmultiplexing (e.g., single-user MIMO or multi-user MIMO),transmit/receive diversity, and/or beamforming. In other examples, thewireless device 1502 and/or the base station 1504 may have a singleantenna.

The processing system 1508 and the processing system 1518 may beassociated with a memory 1514 and a memory 1524, respectively. Memory1514 and memory 1524 (e.g., one or more non-transitory computer readablemediums) may store computer program instructions or code that may beexecuted by the processing system 1508 and/or the processing system 1518to carry out one or more of the functionalities discussed in the presentapplication. Although not shown in FIG. 15, the transmission processingsystem 1510, the transmission processing system 1520, the receptionprocessing system 1512, and/or the reception processing system 1522 maybe coupled to a memory (e.g., one or more non-transitory computerreadable mediums) storing computer program instructions or code that maybe executed to carry out one or more of their respectivefunctionalities.

The processing system 1508 and/or the processing system 1518 maycomprise one or more controllers and/or one or more processors. The oneor more controllers and/or one or more processors may comprise, forexample, a general-purpose processor, a digital signal processor (DSP),a microcontroller, an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) and/or other programmable logicdevice, discrete gate and/or transistor logic, discrete hardwarecomponents, an on-board unit, or any combination thereof. The processingsystem 1508 and/or the processing system 1518 may perform at least oneof signal coding/processing, data processing, power control,input/output processing, and/or any other functionality that may enablethe wireless device 1502 and the base station 1504 to operate in awireless environment.

The processing system 1508 and/or the processing system 1518 may beconnected to one or more peripherals 1516 and one or more peripherals1526, respectively. The one or more peripherals 1516 and the one or moreperipherals 1526 may include software and/or hardware that providefeatures and/or functionalities, for example, a speaker, a microphone, akeypad, a display, a touchpad, a power source, a satellite transceiver,a universal serial bus (USB) port, a hands-free headset, a frequencymodulated (FM) radio unit, a media player, an Internet browser, anelectronic control unit (e.g., for a motor vehicle), and/or one or moresensors (e.g., an accelerometer, a gyroscope, a temperature sensor, aradar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, acamera, and/or the like). The processing system 1508 and/or theprocessing system 1518 may receive user input data from and/or provideuser output data to the one or more peripherals 1516 and/or the one ormore peripherals 1526. The processing system 1518 in the wireless device1502 may receive power from a power source and/or may be configured todistribute the power to the other components in the wireless device1502. The power source may comprise one or more sources of power, forexample, a battery, a solar cell, a fuel cell, or any combinationthereof. The processing system 1508 and/or the processing system 1518may be connected to a GPS chipset 1517 and a GPS chipset 1527,respectively. The GPS chipset 1517 and the GPS chipset 1527 may beconfigured to provide geographic location information of the wirelessdevice 1502 and the base station 1504, respectively.

FIG. 16A illustrates an example structure for uplink transmission. Abaseband signal representing a physical uplink shared channel mayperform one or more functions. The one or more functions may comprise atleast one of: scrambling; modulation of scrambled bits to generatecomplex-valued symbols; mapping of the complex-valued modulation symbolsonto one or several transmission layers; transform precoding to generatecomplex-valued symbols; precoding of the complex-valued symbols; mappingof precoded complex-valued symbols to resource elements; generation ofcomplex-valued time-domain Single Carrier-Frequency Division MultipleAccess (SC-FDMA) or CP-OFDM signal for an antenna port; and/or the like.In an example, when transform precoding is enabled, a SC-FDMA signal foruplink transmission may be generated. In an example, when transformprecoding is not enabled, an CP-OFDM signal for uplink transmission maybe generated by FIG. 16A. These functions are illustrated as examplesand it is anticipated that other mechanisms may be implemented invarious embodiments.

FIG. 16B illustrates an example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued SC-FDMA or CP-OFDM baseband signal for anantenna port and/or a complex-valued Physical Random Access Channel(PRACH) baseband signal. Filtering may be employed prior totransmission.

FIG. 16C illustrates an example structure for downlink transmissions. Abaseband signal representing a physical downlink channel may perform oneor more functions. The one or more functions may comprise: scrambling ofcoded bits in a codeword to be transmitted on a physical channel;modulation of scrambled bits to generate complex-valued modulationsymbols; mapping of the complex-valued modulation symbols onto one orseveral transmission layers; precoding of the complex-valued modulationsymbols on a layer for transmission on the antenna ports; mapping ofcomplex-valued modulation symbols for an antenna port to resourceelements; generation of complex-valued time-domain OFDM signal for anantenna port; and/or the like. These functions are illustrated asexamples and it is anticipated that other mechanisms may be implementedin various embodiments.

FIG. 16D illustrates another example structure for modulation andup-conversion of a baseband signal to a carrier frequency. The basebandsignal may be a complex-valued OFDM baseband signal for an antenna port.Filtering may be employed prior to transmission.

A wireless device may receive from a base station one or more messages(e.g. RRC messages) comprising configuration parameters of a pluralityof cells (e.g. primary cell, secondary cell). The wireless device maycommunicate with at least one base station (e.g. two or more basestations in dual-connectivity) via the plurality of cells. The one ormore messages (e.g. as a part of the configuration parameters) maycomprise parameters of physical, MAC, RLC, PCDP, SDAP, RRC layers forconfiguring the wireless device. For example, the configurationparameters may comprise parameters for configuring physical and MAClayer channels, bearers, etc. For example, the configuration parametersmay comprise parameters indicating values of timers for physical, MAC,RLC, PCDP, SDAP, RRC layers, and/or communication channels.

A timer may begin running once it is started and continue running untilit is stopped or until it expires. A timer may be started if it is notrunning or restarted if it is running. A timer may be associated with avalue (e.g. the timer may be started or restarted from a value or may bestarted from zero and expire once it reaches the value). The duration ofa timer may not be updated until the timer is stopped or expires (e.g.,due to BWP switching). A timer may be used to measure a timeperiod/window for a process. When the specification refers to animplementation and procedure related to one or more timers, it will beunderstood that there are multiple ways to implement the one or moretimers. For example, it will be understood that one or more of themultiple ways to implement a timer may be used to measure a timeperiod/window for the procedure. For example, a random access responsewindow timer may be used for measuring a window of time for receiving arandom access response. In an example, instead of starting and expiry ofa random access response window timer, the time difference between twotime stamps may be used. When a timer is restarted, a process formeasurement of time window may be restarted. Other exampleimplementations may be provided to restart a measurement of a timewindow.

FIG. 17 illustrates examples of device-to-device (D2D) communication, inwhich there is a direct communication between wireless devices. In anexample, D2D communication may be performed via a sidelink (SL). Thewireless devices may exchange sidelink communications via a sidelinkinterface (e.g., a PC5 interface). Sidelink differs from uplink (inwhich a wireless device communicates to a base station) and downlink (inwhich a base station communicates to a wireless device). A wirelessdevice and a base station may exchange uplink and/or downlinkcommunications via a user plane interface (e.g., a Uu interface).

As shown in the figure, wireless device #1 and wireless device #2 may bein a coverage area of base station #1. For example, both wireless device#1 and wireless device #2 may communicate with the base station #1 via aUu interface. Wireless device #3 may be in a coverage area of basestation #2. Base station #1 and base station #2 may share a network andmay jointly provide a network coverage area. Wireless device #4 andwireless device #5 may be outside of the network coverage area.

In-coverage D2D communication may be performed when two wireless devicesshare a network coverage area. Wireless device #1 and wireless device #2are both in the coverage area of base station #1. Accordingly, they mayperform an in-coverage intra-cell D2D communication, labeled as sidelinkA. Wireless device #2 and wireless device #3 are in the coverage areasof different base stations, but share the same network coverage area.Accordingly, they may perform an in-coverage inter-cell D2Dcommunication, labeled as sidelink B. Partial-coverage D2Dcommunications may be performed when one wireless device is within thenetwork coverage area and the other wireless device is outside thenetwork coverage area. Wireless device #3 and wireless device #4 mayperform a partial-coverage D2D communication, labeled as sidelink C.Out-of-coverage D2D communications may be performed when both wirelessdevices are outside of the network coverage area. Wireless device #4 andwireless device #5 may perform an out-of-coverage D2D communication,labeled as sidelink D.

Sidelink communications may be configured using physical channels, forexample, a physical sidelink broadcast channel (PSBCH), a physicalsidelink feedback channel (PSFCH), a physical sidelink discovery channel(PSDCH), a physical sidelink control channel (PSCCH), and/or a physicalsidelink shared channel (PSSCH). PSBCH may be used by a first wirelessdevice to send broadcast information to a second wireless device. PSBCHmay be similar in some respects to PBCH. The broadcast information maycomprise, for example, a slot format indication, resource poolinformation, a sidelink system frame number, or any other suitablebroadcast information. PSFCH may be used by a first wireless device tosend feedback information to a second wireless device. The feedbackinformation may comprise, for example, HARQ feedback information. PSDCHmay be used by a first wireless device to send discovery information toa second wireless device. The discovery information may be used by awireless device to signal its presence and/or the availability ofservices to other wireless devices in the area. PSCCH may be used by afirst wireless device to send sidelink control information (SCI) to asecond wireless device. PSCCH may be similar in some respects to PDCCHand/or PUCCH. The control information may comprise, for example,time/frequency resource allocation information (RB size, a number ofretransmissions, etc.), demodulation related information (DMRS, MCS, RV,etc.), identifying information for a transmitting wireless device and/ora receiving wireless device, a process identifier (HARQ, etc.), or anyother suitable control information. The PSCCH may be used to allocate,prioritize, and/or reserve sidelink resources for sidelinktransmissions. PSSCH may be used by a first wireless device to sendand/or relay data and/or network information to a second wirelessdevice. PSSCH may be similar in some respects to PDSCH and/or PUSCH.Each of the sidelink channels may be associated with one or moredemodulation reference signals. Sidelink operations may utilize sidelinksynchronization signals to establish a timing of sidelink operations.Wireless devices configured for sidelink operations may send sidelinksynchronization signals, for example, with the PSBCH. The sidelinksynchronization signals may include primary sidelink synchronizationsignals (PSSS) and secondary sidelink synchronization signals (SSSS).

Sidelink resources may be configured to a wireless device in anysuitable manner. A wireless device may be pre-configured for sidelink,for example, pre-configured with sidelink resource information.Additionally or alternatively, a network may broadcast systeminformation relating to a resource pool for sidelink. Additionally oralternatively, a network may configure a particular wireless device witha dedicated sidelink configuration. The configuration may identifysidelink resources to be used for sidelink operation (e.g., configure asidelink band combination).

The wireless device may operate in different modes, for example, anassisted mode (which may be referred to as mode 1) or an autonomous mode(which may be referred to as mode 2). Mode selection may be based on acoverage status of the wireless device, a radio resource control statusof the wireless device, information and/or instructions from thenetwork, and/or any other suitable factors. For example, if the wirelessdevice is idle or inactive, or if the wireless device is outside ofnetwork coverage, the wireless device may select to operate inautonomous mode. For example, if the wireless device is in a connectedmode (e.g., connected to a base station), the wireless device may selectto operate (or be instructed by the base station to operate) in assistedmode. For example, the network (e.g., a base station) may instruct aconnected wireless device to operate in a particular mode.

In an assisted mode, the wireless device may request scheduling from thenetwork. For example, the wireless device may send a scheduling requestto the network and the network may allocate sidelink resources to thewireless device. Assisted mode may be referred to as network-assistedmode, gNB-assisted mode, or base station-assisted mode. In an autonomousmode, the wireless device may select sidelink resources based onmeasurements within one or more resource pools (for example,pre-configure or network-assigned resource pools), sidelink resourceselections made by other wireless devices, and/or sidelink resourceusage of other wireless devices.

To select sidelink resources, a wireless device may observe a sensingwindow and a selection window. During the sensing window, the wirelessdevice may observe SCI transmitted by other wireless devices using thesidelink resource pool. The SCIs may identify resources that may be usedand/or reserved for sidelink transmissions. Based on the resourcesidentified in the SCIs, the wireless device may select resources withinthe selection window (for example, resource that are different from theresources identified in the SCIs). The wireless device may transmitusing the selected sidelink resources.

FIG. 18 illustrates an example of a resource pool for sidelinkoperations. A wireless device may operate using one or more sidelinkcells. A sidelink cell may include one or more resource pools. Eachresource pool may be configured to operate in accordance with aparticular mode (for example, assisted or autonomous). The resource poolmay be divided into resource units. In the frequency domain, eachresource unit may comprise, for example, one or more resource blockswhich may be referred to as a sub-channel. In the time domain, eachresource unit may comprise, for example, one or more slots, one or moresubframes, and/or one or more OFDM symbols. The resource pool may becontinuous or non-continuous in the frequency domain and/or the timedomain (for example, comprising contiguous resource units ornon-contiguous resource units). The resource pool may be divided intorepeating resource pool portions. The resource pool may be shared amongone or more wireless devices. Each wireless device may attempt totransmit using different resource units, for example, to avoidcollisions.

Sidelink resource pools may be arranged in any suitable manner. In thefigure, the example resource pool is non-contiguous in the time domainand confined to a single sidelink BWP. In the example resource pool,frequency resources are divided into a Nf resource units per unit oftime, numbered from zero to Nf−1. The example resource pool may comprisea plurality of portions (non-contiguous in this example) that repeatevery k units of time. In the figure, time resources are numbered as n,n+1 . . . n+k, n+k+1 . . . , etc.

A wireless device may select for transmission one or more resource unitsfrom the resource pool. In the example resource pool, the wirelessdevice selects resource unit (n,0) for sidelink transmission. Thewireless device may further select periodic resource units in laterportions of the resource pool, for example, resource unit (n+k,0),resource unit (n+2k,0), resource unit (n+3k,0), etc. The selection maybe based on, for example, a determination that a transmission usingresource unit (n,0) will not (or is not likely) to collide with asidelink transmission of a wireless device that shares the sidelinkresource pool. The determination may be based on, for example, behaviorof other wireless devices that share the resource pool. For example, ifno sidelink transmissions are detected in resource unit (n−k,0), thenthe wireless device may select resource unit (n,0), resource (n+k,0),etc. For example, if a sidelink transmission from another wirelessdevice is detected in resource unit (n−k,1), then the wireless devicemay avoid selection of resource unit (n,1), resource (n+k,1), etc.

Different sidelink physical channels may use different resource pools.For example, PSCCH may use a first resource pool and PSSCH may use asecond resource pool. Different resource priorities may be associatedwith different resource pools. For example, data associated with a firstQoS, service, priority, and/or other characteristic may use a firstresource pool and data associated with a second QoS, service, priority,and/or other characteristic may use a second resource pool. For example,a network (e.g., a base station) may configure a priority level for eachresource pool, a service to be supported for each resource pool, etc.For example, a network (e.g., a base station) may configure a firstresource pool for use by unicast UEs, a second resource pool for use bygroupcast UEs, etc. For example, a network (e.g., a base station) mayconfigure a first resource pool for transmission of sidelink data, asecond resource pool for transmission of discovery messages, etc.

Vehicular communication services, represented by V2X services, maycomprise of the following different types: V2V, V2I, V2N and/or V2P. V2Xservices may be provided by PC5 interface (sidelink) and/or Uu interface(UE to base station interface). Support of V2X services via PC5interface may be provided by V2X sidelink communication, which is a modeof communication whereby UEs may communicate with each other directlyover the PC5 interface.

For V2X communication, a wireless device may provide UE assistanceinformation to an gNB. Reporting of UE assistance information may beconfigured by gNB transmitting one or more RRC messages. The UEassistance information may include parameters related to the SPSconfiguration or configured grant resource configuration. Triggering ofUE assistance information transmission may be left to UE implementation.For instance, the UE may be allowed to report the UE assistanceinformation when change in estimated periodicity and/or timing offset ofpacket arrival occurs.

The wireless device may transmit traffic associated with multiple V2Xservices, which may require different periodicity and packet sizes. TheSPS TB size and period may be adapted to different V2X services.Multiple parallel SPS processes may be activated at the UE. The SPSprocesses may differ in the amount of resource blocks (RBs) allocatedand/or SPS period and may correspond to different types of V2X packets.

In an example, a base station may provide one or more SPS and/orconfigured grant (CG) resource configurations for the UE via RRCsignaling. In an example, multiple SPSs and/or multiple CGs may beactivated in parallel. For example, a new service may be triggered whilea previous service is on-going. In an example, the wireless device maytransmit an assistance message to the base station indicating newinformation about new messages (SPS traffic) for transmission. The basestation may provide a second SPS/CG configuration for the newservice/message(s).

In an example, a base station may configure an assisted mode (e.g. mode1, a first mode) for a resource pool or for a sidelink cell or for asidelink UE for one or more sidelink sessions. In response to beingconfigured with the assisted mode or the first mode, the base stationmay configure one or more SR configurations which are mapped to one ormore logical channels for sidelink sessions. The base station mayconfigure one or more configured grant resources used for the assistedmode or the first mode of the sidelink operation. A wireless device, inresponse new sidelink data available at MAC layer, may transmit the newsidelink data via the one or more configured grant resources ifavailable. The wireless device may trigger a buffer status reporting(BSR) when the wireless device may not have available configured grantresource(s). The wireless device may determine whether the one or moreconfigured grants are available based on logical channels associatedwith the one or more configured grants, logical channels of the newsidelink data, a packet size, MCS of the one or more configured grants,latency requirement, periodicity of the one or more configured grants,and/or the like. The wireless device may trigger the BSR to requestresource allocations from the base station on the assisted mode or thefirst mode.

FIG. 19 illustrates an example of a procedure to request the resourceallocation from the base station for transmission of new sidelink data.A base station (gNB) may configure an assisted mode or a first mode ofsidelink operation to a wireless device (UE1, SL Tx UE). At a time m,the wireless device has new sidelink data available for transmission.The wireless device may trigger a BSR for the new sidelink data. Beforethe time m, the wireless device receives a UL grant scheduling a PUSCHafter the time m. The wireless device may use the PUSCH to carry theBSR. The base station, based on the BSR, may schedule a first sidelinkDCI comprising resource assignments for sidelink transmissions. Thewireless device may transmit the sidelink transmissions based on thesidelink DCI. The wireless device may have another new sidelink dataavailable for transmission at a time n. The wireless device may triggera second BSR for the another new sidelink data. At the time n, there isno scheduled PUSCH to carry the second BSR. The wireless device maytrigger a SR to handle the second BSR. In response to the SR, the basestation may schedule another UL grant for the second BSR. The wirelessdevice may send the second BSR via another PUSCH. Based on receiving theBSR, the base station may schedule a second sidelink DCI. For example,the sidelink DCI may comprise resource assignments for one or moresidelink transmission (e.g., control and data, PSCCH and PSSCH) and/orone or more sidelink feedback resources. The wireless device maytransmit the another new sidelink data in response to receiving thesecond sidelink DCI. A wireless device may receive a sidelink DCI or aDCI comprising one or more resource assignments for sidelinktransmission. The sidelink transmission may comprise one or moresidelink data transmissions (PSSCHs), and one or more sidelink controltransmissions. A receiver wireless device may determine one or morefeedback resources corresponding to the sidelink data transmissionsbased on one or more rules (e.g., based on a fixed timing between aPSSCH and a PSFCH and configured PSFCH resources) or based on thesidelink DCI or the DCI. The sidelink DCI or the DCI may indicate one ormore feedback resources for the receiver wireless device. The sidelinkDCI or the DCI may comprise one or more HARQ-ACK resources. The wirelessdevice may transmit HARQ-ACK feedbacks, via the one or more HARQ-ACKresources, corresponding to the indicated resource assignments and/orthe indicated sidelink transmission. For example, the wireless device,in FIG. 19, may transmit a first HARQ-ACK feedback for a first PSSCH anda second HARQ-ACK feedback for a second PSSCH even though two HARQ-ACKfeedbacks are not shown in the diagram.

FIG. 20 illustrates a diagram of a first mode of sidelink operation. Forexample, a base station may configure the first mode (e.g., mode 1,assisted mode) to a first wireless device. The first wireless device maymonitor one or more DCIs (e.g., sidelink DCIs) comprising resourceassignments for sidelink transmission. The first wireless device maytrigger a SR at a time n. The first wireless device may trigger the SRbased on a BSR. The first wireless device may trigger the BSR upon newsidelink data available to the first wireless device. For example, thefirst wireless device has the new sidelink data for an unicast sidelinksession or a groupcast sidelink session. The base station may schedule aPUSCH via a UL grant in response to receiving the SR (e.g., SL SR). Thefirst wireless device may transmit the BSR via the PUSCH. Based on theBSR, the base station may schedule a DCI (e.g., SL DCI) comprisingresource assignments for sidelink transmissions. The sidelinktransmission may comprise PSCCH and PSSCH. The sidelink transmission maycomprise one or more of PSCCH and PSSCH. A second wireless device, areceiver of the sidelink session of the new sidelink data, may transmita feedback via PSFCH. The first wireless device may transmit a HARQ-ACKfeedback for the sidelink transmission. In response to a broadcasttransmission, the second wireless device may not transmit a feedback tothe first wireless device. The first wireless device may indicateHARQ-ACK with a ACK via SL HARQ to the base station in response to theallocated resources being used for the broadcast transmission.

In an example, a wireless device may trigger a sidelink buffer statusreport (BSR) in response to one or more events occurring. For example,the wireless device operates a sidelink mode 1 operation (e.g., anassisted mode, a first mode, being configured with a sidelink RNTI suchas SL-RNTI) and the wireless device may have new sidelink data availableat a MAC layer and a logical channel of the new sidelink data may not beavailable for any already available sidelink transmissions (e.g., notable to be multiplexed with existing sidelink data for the sidelinktransmissions). In this case, the wireless device may trigger a regularsidelink BSR. For example, the wireless device may have uplink resourcesavailable and number of padding bits remaining after a padding BSR foruplink is added is equal to or larger than a size of the sidelink BSRMAC CE, the wireless device may trigger the sidelink BSR, which iscalled as a padding sidelink BSR. Based on one or more timers, thewireless device may trigger a regular sidelink BSR (e.g., based onretx-BSR-TimerSL) or trigger a periodic BSR (e.g., based onperiodic-BSR-TimerSL).

In existing technologies, a wireless device may trigger a buffer statusreporting (BSR) in response to new sidelink data being available to aMAC layer. The wireless device may transmit the BSR via a scheduledPUSCH if available for carrying the BSR. The wireless device may triggerand transmit an SR to obtain resources for the BSR. Based on the SR, thebase station may transmit an uplink grant to the wireless device. Uponreceiving the uplink grant, the wireless device may transmit the BSR tothe base station using the uplink resources indicated in the uplinkgrant. The BSR may indicate a buffer size level, for example, how muchdata is in a buffer and is to be transmitted. Based on the informationin the BSR, the base station may select resources for sidelinktransmissions and assign them to the wireless device. The base stationmay transmit one or more DCIs comprising resource assignments forsidelink transmissions (e.g., sidelink DCIs, DCIs scrambled with a RNTIfor sidelink operation such as SL-RNTI) for the new sidelink data. Thisprocedure may result in increased latency as messages are exchangedbetween the wireless device and the base station (SR, uplink grant, BSR,DCI), making it ineffective for sidelink applications such asplatooning, industrial collaborations, see through, etc. As analternative, the base station may provide the wireless device with oneor more configured grant resources, allowing the wireless device toperform periodic and/or semi-persistent sidelink transmission withoutwaiting to receive sidelink resources in a DCI. To obtain the configuredgrant resources, the wireless device may provide UE-assistanceinformation for one or more semi-persistent or periodic sidelinksessions. The UE-assistance information may comprise traffic assistanceinformation relating to one or more traffic patterns, where each trafficpattern is associated with a periodicity, a time offset, a message size,a priority, a logical channel, and optionally a destination of asidelink session. The base station may configure the configured grantresources based on the UE-assistance information. However, in someapplications (for example, aperiodic low latency sidelink sessions),configured grants may require that large amounts of resources be setaside, which may be utilized only sporadically. Existing mechanisms maynot efficiently support diverse sidelink application requirements andmay need to be enhanced.

In an example of an enhanced procedure, a wireless device may transmit,to a base station, enhanced traffic assistance information correspondingto a sidelink session (for example, a sidelink session requiring lowlatency). In an example, the enhanced traffic assistance information maycomprise a traffic type indication informing the base station as towhether the sidelink session/traffic is associated with periodic data oraperiodic data. In an example, the enhanced traffic assistanceinformation may comprise a nominal buffer size level. In an example, theenhanced traffic assistance information may comprise an indication of anSR configuration (for example, an SR configuration index) associatedwith the sidelink session/traffic. Based on the enhanced trafficassistance information, the base station may determine to assignsidelink resources using existing procedures (e.g., dynamic schedulingor configured grants) or enhanced procedures in accordance with thepresent disclosure. In an example, the base station may, based on theenhanced traffic assistance information, determine to use an enhancedprocedure that reduces latency while avoiding excessive increases inresource consumption. These advantages may be particularly evident inthe case of sidelink sessions associated with aperiodic trafficrequiring low latency.

In an example, the enhanced procedure may comprise transmitting, by thewireless device, traffic assistance information for a sidelink session.For example, the traffic assistance information may indicate anaperiodic traffic type. The traffic assistance information may indicatean identifier indicating a logical channel associated with a sidelinktraffic/the sidelink session. The traffic assistance information mayindicate one or more periodicities associated with the logical channel.In response to receiving the traffic assistance information, the basestation may transmit one or more RRC messages indicating one or moreconfigured grant configurations. The configured grant configurations maybe determined based on the one or more periodicities of the logicalchannel. When the wireless device has new sidelink data available, thewireless device may transmit, to the base station, trigger atransmission of a buffer status report (BSR). The wireless device maytransmit a scheduling request (SR) in response to the triggering thetransmission of the BSR. The base station may receive the SR and maytransmit, in response to the SR, one or more DCIs comprising sidelinkresources for transmission of the new sidelink data. In response to theSR, the base station may transmit one or more activation commandsindicating activation of the one or more configured grantconfigurations. In response to the transmission of the SR, the wirelessdevice may cancel the BSR.

The base station may reduce a scheduling latency by activating the oneor more configured grant configurations, in response to the SR, withoutwaiting for the wireless device to deliver a BSR. In existingprocedures, the wireless device may complete a SR process when thewireless device may multiplex the BSR or transmit the BSR. Inembodiments, the base station may skip scheduling an UL grant for theBSR. In embodiments, for example, the wireless device may, as part ofthe enhanced procedure, cancel the pending BSR/SR upon receiving the oneor more DCIs (e.g., activation DCI(s) of the one or more configuredgrant configurations). The wireless device may use the sidelinkresources indicated in the one or more DCIs to transmit the new sidelinkdata with reduced latency.

In an example, the base station may select sidelink resources fortransmission of the new sidelink data based on a nominal buffer sizelevel indicated by the enhanced traffic assistance information. In theenhanced procedure described above, the base station may reduce latencyby selecting the assigned resources without waiting for the wirelessdevice to deliver a BSR. The enhanced procedure may further entailselection of sidelink resources (for example, size, location, orimmediacy of sidelink resources) based on the nominal buffer size levelassociated with the sidelink session. As an example, the base stationmay assume, predict and/or estimate the size, location, and/or immediacyof the assigned resources based on the nominal buffer size level. Thebase station may assume a pre-fixed buffer size level in case thewireless device may not have provided one or more parameters or anominal buffer size level for a sidelink session or a logical channelrequiring a low latency scheduling.

Embodiments may allow shorter scheduling latency by allowingpre-indicated information (e.g., a message size, a nominal buffer size)to be used for scheduling for a logical channel or for a sidelinksession by a base station. Embodiments may not require pre-reservedlarge amount of resources for handling aperiodic low latency requiredtraffic, and thus will reduce unnecessary resource booking and increaseresource utilization efficiency.

FIG. 21 illustrates an example. A base station may configure a firstmode of sidelink operation (e.g., an assisted mode, mode 1) for aresource pool, for a wireless device, or for a sidelink cell to thewireless device. The wireless device may provide one or more UEassistance information. For example, the one or more UE assistanceindication may comprise a set of traffic pattern assistance information.A traffic pattern assistance information may comprise one or moreparameters such as a periodicity, a message size, a logical channel, apriority, a destination ID, and/or a traffic type. The traffic patternassistance information may correspond to a sidelink session that thewireless device is a transmitter wireless device. The traffic type mayrepresent whether the traffic pattern is periodic or aperiodic. Thetraffic pattern assistance information may comprise a nominal buffersize level for the traffic/sidelink session. The base station mayutilize the nominal buffer size level, if indicated, in schedulingresources for sidelink transmissions. The wireless device may alsoinform a SR configuration, via the wireless device may transmit SRs ofthe logical channel, associated with the traffic assistance information.For example, the base station may configure one or more SRconfigurations for a logical channel (for example, a plurality of SRconfiguration associated with the logical channel). The wireless devicemay provide an index of a SR configuration used for transmitting SRscorresponding to the logical channel indicated by the traffic assistanceinformation. The base station, in response to receiving the SRs, mayutilize the traffic assistance information for the logical channel. Whenthe wireless device may have new sidelink data available at MAC layer,the wireless device may trigger a BSR. Based on the BSR, wherein the BSRis triggered for one or more logical channels, the wireless device maytrigger a SR for the new sidelink data (e.g., SL SR) and may transmitthe SR at a time n. The base station may schedule one or more DCIscomprising resource assignments for sidelink transmissions of the newsidelink data (e.g., SL DCI). The base station may also schedule a ULgrant to schedule a PUSCH for the BSR. The wireless device may transmitthe sidelink transmissions (e.g., one or more sidelink transport blocksof the new sidelink data) based on the one or more DCIs. The wirelessdevice may transmit the BSR via the PUSCH based on the UL grant. Asecond wireless device (e.g., UE2, SL Rx UE) may transmit a feedback(e.g., PSFCH) in response to the sidelink transmissions (e.g., PSSCH).The wireless device may send HARQ-ACK feedback to the base station forthe allocated resources for the sidelink transmissions.

In an example, a wireless device may indicate one or more parameters fora sidelink session via a UE assistance information. The one or moreparameters may comprise one or more configuration parameters such as alogical channel, a priority of the logical channel (if notavailable/configured by a base station), a periodicity, a message size,a traffic type (e.g., aperiodic or periodic), a sidelink destination ID,MCS or TBS, a number of retransmission/repetition, and/or the like. Thewireless device may have new sidelink data being available to a MAClayer. The wireless device may determine whether a second logicalchannel of the new sidelink data is associated with the sidelink session(e.g., the second logical channel is equal to the logical channel). Forexample, the wireless device may have indicated the one or moreparameters related to the sidelink session to the base station. Thewireless device may trigger a BSR for the new sidelink data. In responseto the determining, the wireless device may trigger a SR for the BSR andtransmit the SR via a valid PUCCH resource based on a SR configuration.A base station may determine whether there is available the one or moreparameters for the sidelink session or for the logical channel. The baesstation may determine one or more predetermined parameters for thesidelink session or for the logical channel based on the priority of oneor more logical channels associated with the SR configuration via the SRis received. Based on the one or more parameters or the one or more(pre-)determined parameters (e.g., based on predetermined values orbased on the UE assistance information), the base station may scheduleone or more DCIs comprising resource assignments for sidelinktransmissions of the new sidelink data. The base station may optionallytransmit an UL grant for a PUSCH for the BSR transmission.

In the example, the wireless device may receive the one or more DCIscomprising resource assignments for the sidelink transmissions of thenew sidelink data. The wireless device may schedule the one or moresidelink transmissions (e.g., one or more sidelink transport blocks ofthe new sidelink data) based on the one or more DCIs. In response to thereceiving the one or more DCIs, the wireless device may cancel thepending/triggered SR, wherein the SR has been triggered for the newsidelink data, based on one or more criteria being met. For example, theone or more criteria may comprise that the SR is associated with one ormore logical channels with one or more priorities. For example, the oneor more priorities are greater than or equal to a first threshold value.For example, the one or more criteria may comprise that the SR istriggered by a logical channel with a priority. For example, thepriority of the logical channel is greater than or equal to a secondthreshold value. For example, the one or more criteria may comprise thatthe one or more DCIs comprising resource assignments. For example, theresource assignments are enough to accommodate one or more sidelinktransport blocks comprising the new sidelink data that has triggered theSR. For example, the one or more criteria may comprise that a size ofthe new sidelink data is aligned with the one or more parameters of thesidelink session informed to the base station via the UE-assistanceinformation. The message/data size of the new sidelink data is small orsimilar size to the message size of the UE-assistance information, thewireless device may cancel the SR in response to receiving the one ormore DCIs. For example, the one or more criteria may comprise that theSR is triggered only for sidelink BSRs. The wireless device may notcancel the SR when the SR is triggered for both sidelink and uplinkBSRs. For example, the one or more criteria may comprise that the SR istriggered for sidelink BSRs for one or more sidelink logical channels.For example, the wireless device may have informed via UE-assistanceinformation on one or more parameters of each sidelink logicalchannel/sidelink session of the one or more sidelink logical channels.The wireless device may not cancel the SR when there is at least one BSRfor a sidelink logical channel mapped to the triggered SR, when the basestation may not schedule DCIs comprising resource assignments withoutreceiving the at least one BSR. For example, the one or more criteriamay comprise that the SR is triggered for one or more second sidelinklogical channels. For example, the one or more second logical channelsare configured to support cancelling the SR in response to receivingsidelink DCIs or are configured to support a low latency enhanced SRprocedure described in the specification.

In response to cancelling the SR when the one or more criteria is met,the wireless device may keep other pending SR(s) sharing a same SRconfiguration to the SR. The wireless device may maintain pending SR(s)of different SR configuration(s) from the SR configuration. The wirelessdevice may reset/stop sr-ProhibitTimer when there is no pending SR otherthan the triggered SR on the SR configuration, where the triggered SRhas been transmitted via the SR configuration. The wireless device maycontinue sr-ProhibitTimer when there is at least one pending SR on theSR configuration. The wireless device may assume sr-ProhibitTimer isexpired when there is a pending SR on the SR configuration, so that thepending SR may be transmitted. The wireless device may reset a number ofretransmission counter for a SR transmission (e.g., SR_COUNTER) inresponse to the cancelling the SR.

In an example, a wireless device may determine a first PUCCH resource ora second PUCCH resource for a SR transmission depending on whether theone or more criteria is being met. For example, the one or more criteriamay comprise (a) a size of new sidelink data triggered the SR is smallerthan or equal to a message size indicated via a UE-assistanceinformation; (b) one-shot small data arrival such that one resourceallocation may be enough and a follow-up BSR transmission may not benecessary; (c) the SR is transmitted via a SR configuration, where theSR configuration is configured with no BSR transmission; (d) thewireless device may have sent the BSR in another uplink data such that anew grant for a PUSCH for the BSR may not be necessary; (e) the wirelessdevice has a low latency data such that scheduling resources withoutreceiving BSR is required; (f) the wireless device has aperiodic lowlatency data such that the base station may schedule resources based onpredetermined buffer size level information available at the basestation. The wireless device may select the first PUCCH resource toinform the one or more criteria is being met. The wireless device mayselect the second PUCCH resource to inform the one or more criteria hasnot being met. In response to receiving the SR via the first PUCCH, thebase station may not schedule the UL grant for the PUSCH, as thewireless device may not have any BSR to inform. In response to receivingthe SR via the second PUCCH, the base station may schedule the UL grantfor the BSR. In response to transmitting the SR via the first PUCCHresource, the wireless device may cancel the SR and the BSR in responseto receiving the one or more DCIs. In response to transmitting the SRvia the second PUCCH resource, the wireless device may keep the SR andthe BSR in response to receiving the one or more DCIs.

FIG. 22 illustrates a flow diagram of embodiments. A wireless device mayhave new sidelink data available at a MAC layer. The wireless device maytrigger a sidelink BSR for the new sidelink data. Based on logicalchannel(s) of the new sidelink data and an PUSCH where the wirelessdevice may carry the BSR and based on a latency requirement associatedwith the logical channel(s), the wireless device may determine whetherto transmit the BSR via the PUSCH. The wireless device transmits thePUSCH carrying the BSR in response to the determining. The wirelessdevice may trigger a SR in other cases. The wireless device may receiveone or more uplink grants comprising resource assignments for uplinkPUSCHs. In response to the receiving the one or more uplink grants, thewireless device may determine whether there is any pending BSR or anydata left for triggering a BSR. The wireless device may piggyback thepending BSR or the BSR when there is any data. For example, logicalchannel(s) of the any data may be multiplexed with the scheduled uplinkPUSCHs. The wireless device may cancel the pending BSR when there is nonew data for BSR transmission via the scheduled uplink PUSCHs. Thewireless device may receive one or more sidelink grants comprisingresource assignments for sidelink transmissions. The wireless device maydetermine whether one or more criteria is being met. In response to theone or more criteria being met, the wireless device may cancel thepending SR. Otherwise, the wireless device may keep the pending SR. Theone or more criteria may be determined based on examples specified inthis specification.

In an example, the wireless device may inform/indicate to the basestation via a UE-assistance information (e.g., via RRC signaling, MACCEs, DCIs) on one or more parameters of the sidelink session or thelogical channel. A sidelink session may be defined as a priority, alogical channel, and a sidelink destination ID for a wireless device.The sidelink session may be defined as a sidelink destination ID for thewireless device. The one or more parameters may comprise one or more ofa (nominal) buffer size level, the logical channel index, MCS, a packetsize, a destination ID, and a periodicity/time offset. The (nominal)buffer size level may indicate an expected buffer size level of a BSR ofthe logical channel/sidelink session when a SR is triggered for thelogical channel assuming the logical channel is configured dedicated toa first SR configuration, where the SR is transmitted via the first SRconfiguration. The wireless device may indicate the expected (nominal)buffer size level based on one or more logical channels associated withthe first SR configuration, when there are more than one logical channelmapped to the first SR configuration. The wireless device may cancel thepending BSR in response to receiving the one or more DCIs and a buffersize level computed in the pending BSR is smaller than or equal to theindicated expected buffer size level via the UE-assistance information(e.g., nominal buffer size level). This is to minimize transmitting theBSR, which the base station has obtained the information already. Thismay reduce resource consumption by reducing unnecessary BSRtransmissions.

In an example, a wireless device may trigger an SR. The SR is consideredas pending until the SR is cancelled. In response to cancelling allpending SR(s) of a SR configuration, sr-ProhibitTimer may be stopped inone or more conditions. The one or more conditions may comprise a firstcase where all pending SR(s) are triggered for uplink and/or sidelinkdata and the MAC PDU is assembled. The MAC PDU may comprise one or moreBSRs accommodating buffer status up to and including a last event thathas triggered the BSR or the SR. The one or more conditions may comprisea second case where all pending SR(s) are triggered by sidelink BSR(s)and a second MAC PDU is assembled. The MAC PDU may comprise one or moreBSRs accommodating buffer status up to and including a last event thathas triggered the sidelink BSR or the sidelink SR. The one or moreconditions may comprise a third case where all pending SR(s) aretriggered by sidelink BSR(s) and the wireless device isconfigured/instructed/being transitioned to a second mode (e.g.,UE-autonomous, mode 2) of sidelink transmission. The one or moreconditions may comprise a fourth case where all pending SR(s) aretriggered by sidelink BSR(s) and one or more DCIs comprising resourceassignments for sidelink transmissions may accommodate all the newsidelink data (pending).

In an example, the wireless device may continue sr-ProhibitTimer inresponse to cancelling the SR and there are pending SR(s) of the SRconfiguration. The wireless device may stop the sr-ProhibitTimer inresponse to receiving one or more uplink grants scheduling PUSCH(s) forthe BSR. For example, the wireless device may carry the BSR via thescheduled PUSCH(s) based on the one or more uplink grants.

In response to receiving one or more sidelink DCIs (e.g., DCIscomprising resource assignments for sidelink transmissions), thewireless device may cancel the triggered SR in response to one or morecriteria being met. The wireless device may cancel one or more pendingsidelink SR(s) sharing a same SR configuration to the cancelled SR andtriggered by one or more logical channels. For example, a highestpriority of the one or more logical channels may be larger than or equalto a threshold value. The one or more criteria may comprise a first casewhere a highest priority of one or more second logical channelstriggering the SR may exceed a second threshold value. The one or morecriteria may comprise a second case where the one or more sidelink DCIsmay accommodate the new sidelink data triggered the BSR and the SR. Theone or more criteria may comprise a third case where the SR is triggeredonly by sidelink BSR(s) and a lowest priority of one or more thirdlogical channels triggered a pending SR sharing the same SRconfiguration to the SR is greater than or equal to a third thresholdvalue.

In an example, one or more triggered sidelink BSRs may be cancelled whenthe one or more sidelink DCIs may accommodate all pending data or allthe new sidelink data (e.g., data in one or more buffers) available forsidelink transmissions. In an example, the wireless device mayreset/restart a retransmission timer of sidelink BSR (e.g.,retx-BSR-TimerSL) in response to completing a sidelink BSR transmission.For example, the wireless device may reset/restart retx-BSR-TimerSL inresponse to receiving the one or more sidelink DCIs. For example, thewireless device may reset/restart retx-BSR-TimerSL in response toflushing a data/transport block of a HARQ process, where thedata/transport block comprises the sidelink BSR. For example, thewireless device may reset/restart retx-BSR-TimerSL in response toflushing a data/transport block of a HARQ process, wherein thedata/transport block comprises the sidelink BSR.

In an example, the wireless device may cancel the SR in response toreceiving the one or more sidelink DCIs, the wireless device may notreceive one or more uplink grants scheduling PUSCH(s) to carry the BSR.The wireless device may keep the pending BSR while the pending SR iscancelled. The base station may reschedule the PUSCH(s) for the BSR. Thewireless device may employ a SR retransmission timer (e.g.,retx-SR-TimerSL) for a SR configuration, where the wireless device mayrestart the retx-SR-TimerSL in response to the cancelling the SR. Inresponse to an expiry of the retx-SR-TimerSL, the wireless device maycheck whether any pending BSR associated with the SR configuration(e.g., one or more logical channels associated with the SRconfiguration). The wireless device may re-trigger a SR in response toidentifying the pending BSR. The wireless device may reset/stop theretx-SR-TimerSL in response to receiving one or more uplink grants or inresponse to multiplexing the BSR for a data transmission or in responseto transmitting the BSR.

In an example, a wireless device may obtain traffic information for oneor more sidelink sessions. Traffic information for a sidelink sessionmay comprise one or more parameters such as a periodicity, a packetsize, data burstiness, inter-arrival time, and variance of packet size.Based on the traffic information, the wireless device may requestresources for sidelink transmission via an enhanced scheduling requestmechanism with lower latency and lower resource waste. For example, thewireless device may provide the base station with first traffic patterninformation via a UE-assistance information for a first sidelinksession. The wireless device may provide the base station with secondtraffic pattern information for a second sidelink session. The firsttraffic information and the second traffic information may comprise oneor more parameters such as a periodicity, a packet size for eachtransmission, a priority or logical channel for the first sidelinksession and the second sidelink session. The first information of thefirst sidelink session may further comprise whether the traffic type isaperiodic or periodic or whether the traffic is started immediately ormay be started later (e.g., a starting time of the first sidelinksession). The base station may configure and activate one or moreconfigured grants in response to receiving a second traffic informationcomprising periodic data. The base station may not configure configuredgrant resources or may configure without activation of one or moresecond configured grants in response to receiving the first trafficpattern information comprising aperiodic traffic type.

In an example, a wireless device may determine whether data associatedwith one or more sidelink sessions may have periodic data or aperiodictraffic type. The wireless device may transmit traffic information to abase station. The traffic information may indicate whether the traffictype associated with the one or more sidelink sessions is periodic oraperiodic. Based on the traffic information, a base station mayconfigure one or more configured grants. For example, the base stationmay configure one or more configured grant resources for one or moreperiodic sidelink sessions. For example, the base station may configureone or more SR configurations for aperiodic sidelink sessions (e.g.,short periodicity SR configurations for a low latency aperiodic sidelinksession) so that the wireless device may request scheduling with a lowoverhead in response to data arrivals for the aperiodic sidelinksessions.

In an example, a wireless device may have new sidelink data available atMAC layer. The wireless device may trigger a BSR for the new sidelinkdata. The wireless device may trigger and transmit a SR for the BSR. Abase station, in response to receiving the SR, may schedule one or moresidelink DCIs comprising resource assignments for one or more sidelinktransmissions of the new sidelink data, based on one or more trafficinformation indicated by the wireless device. For example, the wirelessdevice may indicate a first traffic information comprising a firstlogical channel. When the new sidelink data is associated with the firstlogical channel, the wireless device may transmit the SR associated withthe first logical channel. In response to receiving the SR, the basestation may determine the SR is associated with the first logicalchannel. For the first logical channel, the base station may transmitsidelink scheduling DCIs to the wireless device for the new sidelinkdata. The base station may not have received the BSR from the wirelessdevice for the new sidelink data. The base station may rely on the firsttraffic information for the sidelink scheduling DCIs when the basestation has not received the BSR. The base station may use the BSR andthe first traffic information for the sidelink scheduling DCIs when thebase station has received the BSR. The wireless device, in response toreceiving the sidelink scheduling DCIs, may cancel the triggered SR. Thewireless device may keep one or more other pending SRs withoutcancellation, in response to receiving the sidelink scheduling DCIs. Thewireless device, in response to transmitting the BSR, may cancel allpending SRs on a SR configuration used for the triggered/transmitted SR.

In an example, a wireless device may skip triggering a BSR and maytrigger a SR directly in response to new data arrival at the MAC layer.This may reduce a latency to receive one or more scheduling DCIs. Forexample, when the wireless device may carry the BSR on a PUSCH, a basestation may need to receive one or more PUSCHs of a same TB of initialand retransmission of a same HARQ process. A bit error rate of a PUSCHmay be lower than a bit rate of a SR/PUCCH. When the base station maynot successfully decode an initial PUSCH transmission of the BSR, thebase station may need to request a retransmission, which may increasethe scheduling latency. To minimize the scheduling latency, the wirelessdevice may not generate the BSR when one or more conditions aresatisfied. For example, the one or more conditions may comprise a firstcase where the wireless device may receive new data associated with apriority or a logical channel, where the priority or the logical channelis associated with a special SR configuration. The base station mayconfigure the special SR configuration. For example, the wireless devicemay skip triggering a BSR in response to a SR via the special SRconfiguration. The base station may configure a priority threshold valueto determine one or more special SR configurations. For example, ahighest priority of one or more logical channels associated with a SRconfiguration may be larger than or equal to the priority threshold, thewireless device considers the SR configuration as the special SRconfiguration. For example, the one or more conditions may comprise asecond case where the wireless device may receive new data associatedwith a logical channel. For example, a priority of the logical channelis greater than or equal to a second threshold.

For example, the one or more conditions may comprise a third case wherethe wireless device may be configured by the base station whether totrigger a BSR or not for a logical channel, and the logical channel forthe new data is configured with an option not to trigger the BSR. Forexample, the base station may configure a first option of a regular BSRprocedure or a second option of skipping a BSR for a sidelinkdestination or for a sidelink session. Based on the configuration, thewireless device may determine which option to apply. The configurationbetween the first option and the second option may be configured for aSR configuration. The configuration between the first option and thesecond option may be configured for a sidelink cell or for a sidelinkresource pool. The configuration between the first option and the secondoption may be configured for the wireless device and apply theconfigured option for all logical channels configured to the wirelessdevice.

The wireless device may not trigger a SR via the special SRconfiguration when a sidelink SR timer is running. The wireless devicemay start the sidelink SR timer in response to transmitting the SR forthe special SR configuration. In response to having an expiry of thesidelink SR timer, the wireless device may retransmit the SR or transmita pending SR via the special SR configuration.

FIG. 23 illustrates an example. A base station may configure a firstmode (e.g., an assisted mode, model) of sidelink operation to a wirelessdevice. The wireless device may request/inform data arrival forscheduling resources for sidelink transmissions by the base station onthe first mode of sidelink operation. The wireless device may have newdata available at a MAC layer before a time n. Based on the one or moreconditions being met (e.g., a priority of the new data is higher than orequal to a threshold value, an associated SR configuration is configuredas a special SR configuration), the wireless device may transmit a PUCCHcarrying the SR at the time n without triggering a BSR for the new data.The base station, in response to receiving the SR, may schedule one ormore sidelink DCIs comprising resource assignments for sidelinktransmissions for the new data. The wireless device may schedule thesidelink transmissions (e.g., one or more sidelink transport blocks ofthe new sidelink data) based on the one or more sidelink DCIs. A secondwireless device (e.g., a receiver UE, UE2, SL Rx) may response a HARQfeedback via PSFCH. The wireless device (e.g., a transmitter UE, UE1, SLTx) may transmit a HARQ-ACK feedback to the base station, based on theHARQ feedback from the second wireless device.

FIG. 24 illustrates a flow diagram of embodiments. A wireless device mayreceive new data (e.g., uplink data and/or sidelink data). The wirelessdevice may determine whether one or more conditions are satisfied. Whenthe one or more conditions are met, the wireless device may transmit afirst SR (e.g., a SL SR or an uplink SR) when a SR timer is not runningfor a SR configuration via the first SR is transmitted. The wirelessdevice may reset/restart the SR timer in response to the transmitting ofthe first SR. When the one or more conditions are not met, the wirelessdevice may perform a regular BSR/SR procedure by triggering a BSR forthe new data. The regular BSR/SR procedure may be an existing BSR/SRprocedure. For example, the wireless device may trigger a BSR for thenew data. The wireless device may trigger a second SR in response to theBSR if needed. The wireless device may transmit the BSR via a PUSCH,based on one or more uplink grants. Based on the first SR, a basestation may schedule one or more grants (e.g., sidelink grants or uplinkgrants) comprising resource assignments for the new data. The wirelessdevice, in response to receiving the one or more grants, may cancel oneor more pending first SR(s) on the SR configuration. The wireless devicemay stop the SR timer on the SR configuration.

In an example, a wireless device may trigger a BSR in response to newdata is available to a MAC layer and the one or more conditions are notsatisfied. The wireless device may trigger a SR without triggering theBSR in response to the new data is available to the MAC layer and theone or more conditions are satisfied. For example, the one or moreconditions may comprise that a logical channel of new data is associatedwith a special SR configuration. For example, the special SRconfiguration is configured with an option to skip BSR triggering. Inresponse to the one or more conditions are satisfied, the wirelessdevice may trigger the SR, and may restart/reset a SR timer (e.g.,sr-ProhibitTimer). The wireless device may transmit the triggered SRbased on determining a valid PUCCH for the SR. The wireless device maydetermine a valid PUCCH for the SR by checking (a) the valid PUCCHresource for the SR is available; (b) sr-ProhibitTimer or the SR timeris not running at the time of the valid PUCCH resource; (c) the validPUCCH resource is not overlapping with a measurement gap; (d) the SR istriggered via the special SR configuration or the SR is not associatedwith the special SR configuration and the valid PUCCH resource is notoverlapping with a PUSCH resource (e.g., UL-SCH resource); (e) a numberof retransmission for the SR transmission (e.g., SR_COUNTER) is lessthan an allowed maximum number of retransmission (e.g., sr-TransMax). Inresponse to the determining valid PUCCH for the SR, the wireless devicetransmits the SR via the valid PUCCH resource and increases theSR_COUNTER. The wireless device may reset the sr-ProhibitTimer or the SRtimer.

In an example, a wireless device may trigger a sidelink BSR in responseto receiving new sidelink data at a MAC layer. The wireless device maytrigger a first SR in response to the BSR, when the wireless device maynot have a PUSCH suitable for the BSR based on existing procedures. Thewireless device in response to one or more cases occurring may alsotransmit a second SR when the wireless device receives the new sidelinkdata at the MAC layer. For example, the one or more cases may comprise afirst case, where a highest priority of one or more logical channels forthe new sidelink data is greater than or equal to a threshold value. Inthe example, the wireless device may be configured with more than one SRconfigurations for a logical channel having the highest priority. Forexample, a first SR configuration may be used for the first SR and asecond SR configuration may be used for the second SR. A base stationmay schedule one or more first DCIs comprising resource assignments forsidelink transmissions in response to receiving the second SR. The basestation may utilize one or more UE-assistance information for a sidelinksession, where the sidelink session may be associated with the logicalchannel. The base station may schedule one or more second DCIscomprising resource assignments for uplink transmission for the BSR inresponse to receiving the first SR. In response to receiving the one ormore first DCIs, the wireless device may cancel the second SR.

The wireless device may cancel the first SR when the one or more firstDCIs may accommodate all pending sidelink data. In response to receivingthe second DCIs, the wireless device may generate a MAC PDU comprisingthe BSR. The wireless device may cancel the second SR in response to thegenerating the MAC PDU. The wireless device may cancel the BSR inresponse to the generating the MAC PDU or transmitting the MAC PDU. Inresponse to being configured with more than one SR configurations for alogical channel, a wireless device may select a SR configuration or aPUCCH resource which is an earliest in timing.

For example, the one or more cases may comprise a second case, where aSR configuration associated with a logical channel of the new sidelinkdata may be configured with an option to trigger the second SR with andwithout triggering the first SR. The SR configuration may comprise afirst subset SR configuration and a second subset SR configuration. Thewireless device may transmit the first SR via the first subset SRconfiguration of the SR configuration. The wireless device may transmitthe second SR via the second subset SR configuration of the SRconfiguration.

In an example, a wireless device may be configured with a SRconfiguration. For example, a sr-ProhibitTimer is not configured or thesr-ProhibitTimer is configured with a small value (e.g., 1 slot) for theSR configuration. The wireless device may transmit a first SR and maymaintain a pending SR for the first SR. During the first SR is pendingof the SR configuration, the wireless device may trigger a second SR andmay transmit the second SR as sr-ProhibitTimer may not be running. TheSR configuration may be used to transmit one or more SRs whenever a SRis triggered regardless of on-going/pending SRs. The SR configurationmay be used for triggering a second SR, which is additionally triggeredwhen the one or more cases occur. The SR configuration may be used totransmit SRs in response to the one or more criteria being met. The SRconfiguration may be used to transmit SR in response to the one or moreconditions being met. With a small/near-zero value of sr-ProhibitTimermay allow back-to-back SR transmissions. The base station may, inresponse to receiving the back-to-back SR transmissions, schedule one ormore DCIs comprising resource assignments for sidelink transmissions.The small/near-zero value of sr-ProhibitTimer may allow one or moresidelink sessions may request resources from the base station. It ismore effective, when the wireless device may transmit a SR withouttriggering a BSR in response to new data being available.

FIG. 25 illustrates an example. A wireless device may have new sidelinkdata at a MAC layer available. The wireless device may determine whetherone or more cases occur. In response to the determining that the one ormore cases occur, the wireless device may trigger a second SR via asecond SR configuration. The wireless device may trigger a BSRregardless of whether the one or more cases occur. The wireless devicemay trigger a first SR for BSR. A base station may transmit one or moresidelink grants comprising resource assignments for sidelinktransmissions in response to the second SR regardless of whether thebase station has received the BSR or not. The wireless device may cancelthe second SR in response to receiving the one or more sidelink grants.The base station may schedule one or more uplink grants comprisingresource assignments for uplink transmissions in response to the firstSR for the BSR. The wireless device may cancel the first SR in responseto receiving the one or more uplink grants and/or in response tomultiplexing data with the BSR and/or in response to transmitting theBSR and/or in response to transmitting all pending sidelink data. In anexample, the wireless device may not have a valid PUCCH resource for thesecond SR. The wireless device may skip transmitting the second SR andmay cancel the second SR in response to the case where no valid PUCCHresource is available for the second SR. The wireless device maycontinue maintaining other pending SRs. In an example, the wirelessdevice may reach a maximum number of the second SR (re)-transmissions.The wireless device, in response to reaching the maximum number ofretransmissions, the wireless device may skip transmitting the second SRand may cancel the second SR in response to the case where the number ofretransmissions reaches an allowed maximum number. The wireless devicemay continue maintaining other pending SRs. The wireless device maycancel the second SR and may stop a SR timer (e.g., sr-ProhibitTimer).

In an example, a wireless device may trigger a sidelink buffer statusreporting (SL BSR) in response to new sidelink data of a logical channelmay arrive to a MAC layer of the wireless device. The wireless devicemay trigger a first scheduling request (SR) based on the triggering ofthe SL BSR. For example, the wireless device may not identify a PUSCH tocarry the SL BSR. For example, if identified, the PUSCH may satisfy alatency requirement of the SL BSR and/or the PUSCH is allowed totransmit the SL BSR and/or the BSR may be multiplexed with a data forthe PUSCH. The wireless device may receive from a base station one ormore DCIs comprising resource assignments for sidelink transmissions forthe new sidelink data. The wireless device may cancel the first SR inresponse to the receiving the one or more DCIs. The wireless device maytransmit one or more sidelink transport blocks of the new sidelink data(e.g., one or more sidelink transport blocks of the new sidelink data)based on the one or more DCIs. The wireless device may determine whetherthe one or more sidelink transport blocks comprise the new sidelinkdata. The wireless device may trigger and transmit a second SR based onthe determining. For example, the wireless device may skiptriggering/transmitting the second SR in response to no new sidelinkdata of the logical channel after transmitting the one or more sidelinktransport blocks is left. For example, the wireless device may transmitthe second SR in response to the remained new sidelink data of thelogical channel after transmitting the one or more sidelink transportblocks. For example, the wireless device may trigger/transmit the secondSR in response to the pending BSR after the transmitting the one or moresidelink transport blocks.

In an example, a base station may configure a first SR configuration toa logical channel for sidelink data. The base station may configure asecond SR configuration to the logical channel for the sidelink data.The logical channel may be associated with a sidelink session and may beconfigured with a priority. A wireless device may inform/indicate to thebase station via a UE-assistance information (e.g., via RRC signaling,MAC CEs, DCIs) on one or more parameters of the sidelink session. Theone or more parameters may comprise one or more of a buffer size level,the logical channel index, MCS, a packet size, a destination address,and a periodicity. The buffer status report may indicate an expectedbuffer status report in response to trigging the SR of the logicalchannel assuming the logical channel is configured dedicated to thefirst SR configuration. The wireless device may indicate the expectedbuffer size level based on one or more logical channels associated withthe first SR configuration, when there are more than one logicalchannels mapped to the first SR configuration.

The wireless device may have new sidelink data available at a MAC layer.The wireless device may trigger a BSR for the new sidelink data. Thewireless device may determine a buffer size level of the BSR is lowerthan or equal to the buffer size level of the one or more parameters ofthe sidelink session via the UE-assistance information. In response tothe determining (e.g., the buffer size level of the BSR is not greaterthan the reported buffer size level), the wireless device may trigger afirst SR via the first SR configuration. The wireless device may cancelthe BSR in response to transmitting the first SR. The wireless devicemay cancel the first SR in response to receiving one or more sidelinkDCIs comprising resource assignments for sidelink transmissions. Inresponse to the not-determining (e.g., the buffer size level of the BSRis greater than the reported buffer size level), the wireless device mayinitiate a normal BSR/SR procedure as the wireless device may need totransmit the BSR to the base station. In an example, the wireless devicemay trigger a second SR when there is no PUSCH for the BSR. The wirelessdevice may transmit the second SR via the second SR configuration. In anexample, the wireless device may trigger the BSR in response todetermining that the buffer size level of the BSR is greater than thebuffer size level of the one or more parameters of the sidelink sessionindicated via the UE-assistance information. The wireless device mayadditionally trigger the first SR in the example. The wireless devicemay not cancel the BSR and may trigger the second SR if needed. Thewireless device may continue BSR procedure and the first SR procedure inparallel.

FIG. 26 illustrates an example. A base station may configure a first SRconfiguration and a second SR configuration mapped to a first logicalchannel. The base station may further configure a first priority valuethat may be used for the first SR configuration. When the base stationconfigures the priority value for the first SR configuration, thewireless device may use the first SR configuration only when a new datamay comprise data with a priority higher than or equal to the firstpriority value configured for the first SR configuration and logicalchannel(s) of the new data are mapped to the first SR configuration(e.g., the logical channel(s) comprise the first logical channel). Thewireless device may inform one or more traffic pattern informationcomprising the first logical channel or a second priority that is higherthan or equal to the first priority. The base station may associate theone or more traffic pattern information to the first SR configuration.The wireless device may indicate, via the one or more traffic patterninformation, a nominal BSR level of the logical channel or the secondpriority of a sidelink session.

The wireless device may receive second new data available at a MAClayer. In response to the second new data being available, the wirelessdevice may trigger a BSR for the second new data. The wireless devicemay determine whether to transmit a first SR via the first SRconfiguration or a second SR via the second SR configuration based onone or more criteria. For example, the one or more criteria may comprisewhether a computed buffer size level of the triggered BSR exceeds thenominal buffer size level indicated via the one or more traffic patterninformation. When the computed buffer size level exceeds the indicatedbuffer size level, the wireless device may not trigger the first SR viathe first SR configuration. The wireless device may perform a regularBSR/SR procedure. The wireless device may determine a PUSCH to carry theBSR. When the PUSCH is not available, the wireless device may triggerthe second SR and may transmit the second SR via a valid PUCCH resource.When the computed buffer size level is smaller than or equal to theindicated buffer size level, the wireless device may trigger the firstSR via the first SR configuration. The wireless device may transmit thefirst SR via a PUCCH when there is valid PUCCH resource(s) based on thefirst SR configuration. The wireless device may cancel the triggered BSRin response to the transmitting the first SR.

FIG. 27 illustrates a similar example, where the wireless device mayperform a BSR procedure and a first SR procedure in parallel. Thewireless device may trigger the first SR when the one or more criteriabeing met. The wireless device may additionally trigger the second SRfor the BSR transmission. The base station may schedule one or moresidelink DCIs comprising resource assignments for sidelink transmissionsin response to receiving the first SR. The base station may schedule oneor more uplink grants comprising resource assignments for PUSCH(s) inresponse to receiving the second SR. The wireless device may transmitthe sidelink transmissions based on the one or more sidelink DCIs. Thewireless device may transmit the BSR based on the one or more uplinkgrants.

FIG. 28 illustrates a flow diagram of embodiments. FIG. 28 is a similarflow diagram to FIG. 26 with a few differences. For example, thewireless device may trigger the first SR and the second SR in parallel.For example, the wireless device may trigger the first SR and perform anormal BSR/SR procedure in parallel additionally, when the one or morecriteria is being met. The wireless device may not cancel the BSR inresponse to transmitting the first SR, as the wireless device is runningthe normal BSR/SR procedure in parallel.

In an example, a wireless device may transmit one or more parameters fora sidelink session or for a logical channel via a UE-assistanceinformation. The wireless device may transmit the one or more parametersvia one or more RRC messages or MAC CEs or DCIs. The wireless device maysend one or more UE-assistance information for one or more sidelinksessions. The one or more parameters of each sidelink session maycomprise one or more of the followings. For example, the one or moreparameters may comprise a periodicity of data occurrence of the sidelinksession (e.g., trafficPeriodicity) and an offset of the data occurrencein an interval based on the periodicity (e.g., timeOffset). The one ormore parameters may comprise a priority value and/or a logical channelindex/identify (e.g., priorityInfoSL, logicalChannelIdentifyUL). Whenone or more priorities are mapped to a logical channel with a limitednumber of logical channels, the wireless device may further indicate apriority value for the logical channel. In terms of a priority of alogical channel, when there are more than one priority mapped to thelogical channel, may be determined based on a highest priority of themore than one priorities mapped to the logical channel. The priority ofthe logical channel may be determined based on a highest priority ofdata mapped to the logical time at a given time (e.g., data available toa MAC layer may determine the priority). The priority of the logicalchannel may be determined based on a lowest priority of the one or morepriorities. The priority of the logical channel may be determined basedon one or more configuration parameters configured by the base stationon the logical channel (e.g., a priority value of the logical channel).

For example, the one or more parameters of the sidelink session maycomprise a message size where the message size may comprise a size ofdata at an occurrence. The one or more parameters may comprise adestination identify (e.g., trafficDestination) of the sidelink session(e.g., a destination address for a unicast, a group membership addressfor a groupcast, a broadcast group or a broadcast identify for abroadcast). The one or more parameters may further comprise one or morequality of service requirements such as latency (e.g., a delay budget)and reliability (e.g., a required number of repetition) requirements(e.g., latencyInfoSL, reliabilityInfoSL). The one or more parameters mayfurther comprise modulation order (e.g., MCS, modulationIndex) for thesidelink session. The one or more parameters may further comprise anominal buffer size level. For example, the nominal buffer size levelmay represent an expected buffer size level in response to a SR triggerfor the indicated logical channel or for an associated SR configuration.The base station may determine the associated SR configuration based onthe logical channel. For example, the wireless device determines theassociated SR configuration based on one or more RRC configurationparameters of mapping between each logical channel and each SRconfiguration. The nominal buffer size level may be assumed to be sameas the message size when the nominal buffer size level is not indicatedby the wireless device. The base station may determine the nominalbuffer size level based on the periodicity, the message size and aninterval of the associated SR configuration to the logical channel. Forexample, the periodicity is 2 msec, and the message size is 200 bytesand the SR configuration periodicity/interval is 10 msec. The basestation may determine the nominal buffer size level as the messagesize*ceil (SR periodicity/the periodicity) (e.g., a number of messageoccurrences in each SR period or in a delay budget of the logicalchannel) (e.g., 200 bytes*5=1000 bytes).

For example, the one or more parameters may comprise a traffic type suchas aperiodic and periodic. The aperiodic traffic type may refer that theindicated sidelink session may occur aperiodically and may last for acertain duration once started. Indication of periodic or aperiodic of atraffic pattern may be implicitly performed. For example, a periodicityless than a threshold periodicity (e.g., 3 msec), the traffic pattern isconsidered as aperiodic traffic type. The periodicity is equal to orlarger than the threshold periodicity may be considered as periodic. Forexample, one or more first parameters for aperiodic traffic type for afirst sidelink session and one or more second parameters for periodictraffic type for a second sidelink session may be different. Forexample, the one or more first parameters may comprise a plurality of {aperiodicity, a time offset}. For each {a periodicity, a time offset}, amessage size may be additionally configured. One aperiodic sidelinksession may be represented by a plurality of periodic traffic patternsor a plurality of pairs of periodicity and time offset. For aperiodictraffic pattern, the wireless device may provide a plurality ofperiodicities where union of the plurality of periodicities mayrepresent a burstiness of the aperiodic traffic pattern. The one or moreparameters may further comprise a session duration where the traffic mayoccur for the session duration in case of the aperiodic traffic typepattern. The base station may configure one or more configured grantresources for one or more first sidelink sessions indicated withperiodic traffic type. The base station may not configure configuredgrant resources for one or more second sidelink sessions indicated withaperiodic traffic type. The base station may configure one or more shortinterval/periodicity SR configurations for the one or more secondsidelink sessions such that the wireless device may inform an occurrenceof the data with a lower latency to the base station. The base stationmay schedule one or more DCIs comprising resource assignments forsidelink transmissions for the one or more second sidelink sessionsregardless of whether the base station may have received correspondingBSRs or not. The base station may utilize one or more UE-assistanceinformation on the one or more second sidelink sessions in schedulingthe one or more DCIs.

In an example, a wireless device may provide a plurality of nominalbuffer size levels for a sidelink session or for a logical channel orfor a pair of {a priority, a logical channel index}. The plurality ofnominal buffer size levels may be used by a base station to determineresources for sidelink transmissions in response to receiving a SR forthe logical channel. The wireless device may further indicate a nominalbuffer size level among the plurality of nominal buffer size levelsalong with the SR transmission. When the wireless device may notindicate the nominal buffer size level, the base station may select onelevel based on one or more rules. For example, the base station maystart from a lowest buffer size level of the plurality of nominal buffersize levels and may increase in response to receiving a SR for thelogical channel. The base station may reset to the lowest buffer sizelevel when no SR has been received for the logical channel for more thana certain duration (e.g., inactivity timer). For example, the basestation may randomly select a buffer size level among the plurality ofbuffer size levels. For example, the base station may select a buffersize level based on activities of the sidelink session/logical channel.

In an example, a wireless device may not provide a nominal buffer sizelevel for a sidelink session. A base station, without having apre-exchanged nominal buffer size level, may schedule one or more uplinkgrants for PUSCH(s) for receiving a BSR for new sidelink data for thesidelink session. The wireless device may transmit the BSR on thePUSCH(s). In response to receiving the BSR, the base station may use abuffer size level in the BSR as the nominal buffer size level for thesidelink session. The base station may use a most recent buffer sizelevel reported by the wireless device as the nominal buffer size levelfor the sidelink session or for a logical channel. For example, thewireless device may provide a first nominal buffer size level via aUE-assistance information via RRC signaling. The wireless device maytransmit a second BSR based on one or more conditions specified in thespecification via MAC CE signaling. The base station may update thenominal buffer size of the sidelink session, or the logical channelbased on the second BSR. For example, the second BSR is a most recentbuffer size level report from the wireless device. The base station mayuse the updated nominal buffer size level for scheduling resources forsidelink transmissions when an up-to-date buffer size level report for atriggered SR is not available. The base station may use the up-to-datebuffer size level report when available for the scheduling. Whether thebase station may update the nominal buffer size level for the sidelinksession or not may depend on the base station implementation. Thewireless device may indicate a bit in a BSR to inform to the basestation whether the BSR represents a nominal buffer size level so thatthe base station is recommended to update the nominal buffer size levelfor the logical channel or the sidelink session. The wireless device mayindicate otherwise, where the buffer size level of the BSR may not be atypical value of the traffic pattern. This may be indicated via a singlebit (e.g., 0 for not recommending the update, 1 for recommending theupdate) in a BSR MAC CE for each sidelink session or a logical channelor a sidelink traffic.

In an example, a base station may configure one or more parameters of anominal buffer size level assumption for a SR configuration. The one ormore parameters may indicate that the base station may assume theindicated buffer size level for scheduling corresponding logicalchannel(s) associated with the SR configuration. A wireless device mayhave new sidelink data available at a MAC layer. The wireless device maytrigger a BSR and compute a first buffer size level for the BSR. When alogical channel of the new sidelink data is associated with the SRconfiguration with the one or more parameters, the wireless device maydetermine the first buffer size level of the BSR is greater than thenominal buffer size level indicated by the base station. In response tothe determining, the wireless device may continue BSR process and maytrigger a corresponding SR. The wireless device may determine the firstbuffer size level is equal to or smaller than the nominal buffer sizelevel. In response to the determining, the wireless device may trigger aSR via the SR configuration. In response to transmitting the SR, thewireless device may cancel the BSR.

In an example, a wireless device may provide a minimum buffer size levelfor a sidelink session or a logical channel or a pair of {a priority, alogical channel} or for a sidelink traffic. A base station may utilizethe minimum buffer size level to schedule one or more DCIs comprisingresource assignments for sidelink transmissions before the base stationreceives a BSR for the sidelink session or the logical channel or thepair of {a priority, a logical channel} or for the sidelink traffic.This may be used to receive by the wireless device minimum amount ofdata for sidelink transmissions before providing the BSR to the basestation. A default value for the minimum buffer size level would bezero, and may be indicated with a non-zero value for low latency highpriority sidelink data/logical channels. The base station may scheduleuplink grants for the BSR in parallel with the one or more DCIs so thatthe wireless device may transmit the BSR fast. Based on the updated BSRinformation, the base station may continue scheduling more DCIs. Forexample, the minimum buffer size level may be preconfigured/configuredby the base station for a sidelink session or a logical channel or apair of {a priority, a logical channel} or for a sidelink traffic. Thewireless device may cancel the BSR when a buffer size level of the BSRis smaller than or equal to the minimum buffer size level of thesidelink session or the logical channel or the pair of {a priority, alogical channel} or for the sidelink traffic. Otherwise, the wirelessdevice may continue a normal BSR/SR procedure.

In an example, when a nominal or minimum buffer size level is associatedwith a sidelink session, a logical channel, a pair of {a priority, alogical channel}, a sidelink destination index, or a sidelink traffic,the wireless device may trigger a SR when one or more cases. Forexample, the wireless device may trigger the SR as long as an earliestvalid SR occasion for a SR configuration associated with the logicalchannel comes before a PUSCH. For example, the wireless device may carrythe BSR via the PUSCH. For example, the wireless device may trigger theSR when an earliest valid SR occasion for the SR configurationassociated with the logical channel occurs within a latency budget or athreshold duration (e.g., within 2 msec). This is to indicate the SR tothe base station immediately so that the base station may startscheduling resources based on the nominal or minimum buffer sizeassumption for the sidelink session.

In an example, a base station may transmit one or more DCIs activatingone or more configured grant resources in response to receiving a SRassociated with a first logical channel or associated with a firstsidelink session. This may be useful for periodic sidelink sessions orperiodic sidelink traffic pattern. The base station may preconfigure oneor more semi-persistent, periodic or configured grant resources forperiodic sidelink traffic pattern based on UE-assistance information.The base station may activate in response to receiving the SR associatedwith the sidelink traffic pattern.

FIG. 29 illustrates an example of the one or more parameters via RRCsignaling mechanism. A similar mechanism and/or a similar set ofparameters may be also applied/transmitted to MAC CE signaling based orDCI signaling based. For example, a wireless device may send one or moretraffic pattern information via one or more UE-assistance informationRRC messages. For example, a traffic pattern information may compriseone or more parameters of a sidelink session or a sidelink traffic. Theone or more parameters of the traffic pattern information may compriseone or more of a periodicity, a time offset, a priority value, a logicalchannel index, a message size, a traffic destination identify, areliability information/requirement, a latency information/requirement,a MCS (e.g., modulation index), a nominal buffer size level, a traffictype, a cast type, and/or the like. The one or more parameters of thetraffic information may be different based on a cast type (e.g., aunicast, groupcast, broadcast) or may be different based on a traffictype (e.g., aperiodic or periodic). For example, a broadcast type datamay not require a HARQ feedback from one or more receiver UEs. Forgroupcast and/or unicast, the wireless device may indicate whether thewireless device may like to enable HARQ feedback from one or morereceiver UEs via the one or more parameters of the sidelink session. Thebase station, based on the information, may schedule one or moresidelink DCIs comprising resource assignments for one or more sidelinkcontrol channels (PSCCHs), one or more sidelink data channels (PSSCHs),one or more sidelink feedback channels (PSFCHs), and/or one or moreHARQ-ACK feedbacks (PUCCHs) to the base station. The wireless device mayindicate ‘HARQ-ACK’ enabled/disabled for a unicast and/or a groupcastsidelink session such that the base station may assign appropriateresources.

For example, the wireless device may inform, via a UE-assistanceinformation indication, a first set of traffic pattern information for aperiodic sidelink session. For example, the first set of traffic patterninformation may comprise a periodicity, a time offset and a messagesize. The first set of traffic pattern information may further comprisea starting time or a delay to start the session (e.g., a time durationuntil the session may become active). The wireless device may inform,via the UE-assistance information indication, a second set of trafficpattern information. For example, the second set of traffic informationmay comprise a mean/average periodicity, a (standard) deviation of theperiodicity, a mean/average message size, a (standard) deviation of themessage size, and a time offset. The aperiodic traffic type may producedata in a burst manner. The wireless device may indicate a potentialburstiness information via indicating an average/mean value ofperiodicity/message size and deviation values of theperiodicity/message. The second set of traffic information may comprisea starting time and/or a duration of the session being active.

In an example, the wireless device may indicate a preference ofconfiguration of one or more configured grants for a sidelink sessionvia the UE-assistance information. For example, the wireless device mayinform a parameter such as request for configured grant. For example,the parameter may indicate a preference of the wireless device in termsof being configured with configured grant resources for thecorresponding sidelink link session or corresponding traffic pattern.The wireless device may indicate the preference of the configured grantresource for one or more periodic traffic patterns/sidelink sessions.

In an example, a base station may configure one or more configured grantresources (e.g., semi-persistent uplink resources) for a logical channelof a sidelink data, based on a UE-assistance information. The one ormore configured grant resources are used for sidelink transmissions. Awireless device may provide one or more parameters of the logicalchannel of the sidelink data. The one or more parameters may comprise aperiodicity of a traffic pattern, a time offset, a message size and thelogical channel index (and/or a priority). The wireless device mayprovide the one or more parameters of the logical channel of thesidelink data, where the sidelink data may not occur periodic manner.For example, a size of data may change over a time depending onscenarios, which may be larger or smaller than the message size indifferent times. For example, the periodicity may change to be shorteror longer. The one or more parameters may represent average or meanparameters of the traffic pattern for the sidelink data.

The one or more configured grant resources may be configured based onthe one or more parameters. For example, the one or more configuredgrant resources may be enough or may not be sufficient depending onactual new data size occurring. For example, the base station allows tomultiplex new sidelink data of the logical channel and be transmittedvia the one or more configured grant resources based on mapping betweenlogical channels and configured grant resources. The wireless device mayhave new first sidelink data available at a MAC layer. The wirelessdevice may trigger a sidelink BSR in response to one or more eventsoccurring. For example, the one or more events may comprise a first casewhere a next valid configured grant resource of the one or moreconfigured grant resources may not occur in a delay budget of thelogical channel or the new sidelink data (e.g., 3 msec for platooning).In the first case, the wireless device may not be able to use the nextvalid configured grant resource due to a latency and/or reliability(e.g., a number of slots/repetitions configured for the next validconfigured grant resource). For example, the latency is not satisfying arequired latency requirement of the logical channel and/or thereliability or required repetition may not be sufficient compared to arequired repetition number of the logical channel. The wireless devicemay determine the next valid configured grant resource which is anearliest configured gran resource for sidelink transmissions allowed tobe used for the logical channel. The one or more events may comprise asecond case where the wireless device may identify valid configuredgrant resource(s) for the new sidelink data with satisfying the latencyand the reliability requirement of the logical channel and the validconfigured grant resource(s) may not accommodate all the new sidelinkdata (and thus may have a left data after transmitting sidelinktransport blocks via the valid configured grant resource(s)).

For example, for the second case, the wireless device may trigger asidelink BSR based on a short-periodic-sidelink-BSR-Timer (e.g.,short-periodic-BSR-TimerSL). The wireless device may start theshort-periodic-BSR-TimerSL in response to having the new sidelink dataavailable at the MAC layer or in response to transmitting sidelinktransmissions via the valid configured grant resource(s). In an expiryof the short-periodic-BSR-TimerSL, the wireless device may trigger thesidelink BSR if there is no pending sidelink BSR and the wireless devicemay stop the short-periodic-BSR-TimerSL. The wireless device may stopthe short-periodic-BSR-TimerSL in response to triggering a sidelink BSRfor the new sidelink data (e.g., regular-BSR-SL, padding-BSR-SL,periodic-BSR-SL, retx-BSR-SL).

For example, for the second case, the wireless device may trigger asidelink BSR in response to having new sidelink data available at theMAC layer. The wireless device may compute a first buffer size level ofthe logical channel. The wireless device may compute an aggregatedmessage size based on the one or more configured grants where theaggregated message size may comprise a message size of a configuredgrant resource and a number of occasions of the one or more configuredgrants within a delay budget (e.g., the message size is 100 bytes andthree occasions within 20 msec becomes 300 bytes aggregated messagesize). For a low latency, a single occasion may be assumed and theaggregated message size may be the message size of each configured grantresource. The wireless device may compare the first buffer size leveland the aggregated message size. In response to the first buffer size issmaller than or equal to the aggregated message size, the wirelessdevice may cancel the sidelink BSR and transmit one or more firstsidelink transport blocks of the new sidelink data via the configuredgrant resource(s). In response to the first buffer size is larger thanthe aggregated message size, the wireless device may proceed with thesidelink BSR. The wireless device may transmit one or more secondsidelink transport blocks of the new sidelink data via the configuredgrant resource(s). For example, the one or more second sidelinktransport blocks may not comprise the entire new sidelink data.

For example, for the second case, the wireless device may triggerblindly (e.g., without considering one or more conditions) a sidelinkBSR in response to having new sidelink data of the logical channelavailable at the MAC layer. The base station may configure a blindsidelink BSR triggering option for one or more logical channels. For thelogical channel belonging to the one or ore logical channels, thewireless device may trigger the sidelink BSR in response to having thenew sidelink data being available at the MAC layer. This sidelink BSRmay be called as a blind-BSR-SL. The wireless device may handle theblind-BSR-SL in a similar manner to handle a periodic-BSR-SL. Thesidelink BSR may be cancelled in response to transmitting the newsidelink data via one or more sidelink transmissions.

For example, for the second case, the wireless device may trigger asidelink BSR in response to new sidelink data being available to the MAClayer. The wireless device may compute a buffer size level for thesidelink BSR in consideration of one or more sidelink transport blockstransmitted via the valid configured grant resource(s). The wirelessdevice may cancel the sidelink BSR in response to the buffer size levelbecomes zero or very negligible. The wireless device may not trigger ormay cancel a triggered SR in response to the buffer size level becomeszero or very negligible. For example, for the second case, the wirelessdevice may provide the message size of the logical channel via theUE-assistance information. The wireless device may trigger a sidelinkBSR in response to the message size via the UE-assistance information issmaller than a size of the new sidelink data of the logical channel. Forexample, for the second case, the base station may provide a messagesize of the one or more configured grant resource(s). The wirelessdevice may trigger a sidelink BSR in response to the message size of theconfigured grant resource(s) is smaller than a size of the new sidelinkdata of the logical channel.

The one or more events may comprise a third case where the logicalchannel may not be associated or mapped to any configured grant resourcefor sidelink transmission. This may address aperiodic traffic patternmapped to the logical channel, where the wireless device and the basestation may interactively schedule resources based on real-time trafficdemands. For example, when the logical channel may be associated ormapped to one or more configured grant resources for sidelinktransmission, the wireless device may not trigger a BSR for the logicalchannel. The wireless device may utilize the one or more configuredgrant resources for the logical channel. The wireless device may sendupdated UE-assistance information on the logical channel in response toidentifying the one or more configured grant resources may not be enoughfor the logical channel. The wireless device may consider this behavioronly for activated configured grant resources. A configured grantresource configured but not being activated may not be considered forthe third case.

In an example, a configured grant resource for sidelink transmission maybe mapped to a logical channel and/or a sidelink session. The configuredgrant resource may not be shared among a plurality of logical channelsand/or sidelink destinations and/or sidelink sessions.

Embodiments are described mainly focused on a sidelink operation andsidelink new data. It is noted that embodiments may be also applied toan uplink operation and uplink new data. Embodiments may be applied to amixed data of uplink and sidelink data.

In an example, a wireless device may trigger a sidelink buffer statusreporting (SL BSR) in response to new sidelink data of a logical channelmay arrive to a MAC layer of the wireless device. The wireless devicemay trigger a scheduling request (SR) based on the triggering of the SLBSR. For example, the wireless device may not identify a PUSCH to carrythe SL BSR. For example, if identified, the PUSCH may satisfy a latencyrequirement of the SL BSR and/or the PUSCH is allowed to transmit the SLBSR and/or the BSR may be multiplexed with a data for the PUSCH. Thewireless device may receive from a base station one or more DCIscomprising resource assignments for sidelink transmissions for the newsidelink data. In response to the receiving the one or more DCIs, thewireless device may cancel the SR. The wireless device may maintain thepending BSR. The wireless device may cancel the BSR in response totransmitting the BSR or in response to multiplexing the BSR to a datafor a PUSCH or in response to identifying no pending sidelink data isavailable for the logical channel or for a SR configuration mapped tothe logical channel. The wireless device may transmit one or moresidelink transport blocks of the new sidelink data based on the one ormore DCIs (e.g., sidelink scheduling DCIs).

The wireless device may cancel the SR in response to the receiving theone or more DCIs and one or more criteria are being met. The one or morecriteria may comprise a first case where a priority of the logicalchannel (e.g., the priority of the new sidelink data, the highestpriority of the logical channel, the priority configured by the basestation to the wireless device for the logical channel) is greater thanor equal to a threshold. The one or more criteria may comprise that a SRconfiguration (e.g., PUCCH resources or PUCCH resource set for the SRconfiguration) used for the triggered SR may be configured by the basestation with one or more parameters enabling the cancelling the SR inresponse to receiving the one or more DCIs comprising resourceassignments for sidelink transmissions. The one or more criteria maycomprise that the logical channel is configured with one or moreparameters enabling the cancelling the SR in response to receiving theone or more DCIs comprising resource assignments for sidelinktransmissions.

The wireless device may start/restart a retransmission timer (e.g., aSR-retx-timer) for a SR retransmission in response to the cancelling thesidelink scheduling request. The wireless device may have a pending BSRfor the SR configuration used for the SR transmission. The wirelessdevice may stop the retransmission timer (e.g., the SR-retx-timer) inresponse to receiving one or more uplink grants scheduling PUSCH(s). Thewireless device may carry the SL BSR via the PUSCH(s). The wirelessdevice may retransmit the SR in response to an expiry of theretransmission timer (e.g., the SR-retx-timer) and the SL BSR ispending. The wireless device may stop the retransmission timer inresponse to the cancelling the SL BSR.

The wireless device may continue a prohibit timer for the SRconfiguration (e.g., sr-ProhibitTimer) in response to the cancelling theSR. The wireless device may stop the sr-ProhibitTimer in response toreceiving the one or more uplink grants scheduling the PUSCH(s). Forexample, the wireless device may carry the SL BSR via the PUSCH(s).

In an example, the wireless device may indicate to the base station oneor more parameters for the new sidelink data of the logical channel. Theone or more parameters may comprise a periodicity, a time offset, amessage size, a priority and the logical channel index. The one or moreparameters may further comprise a buffer size level. For example, theindicated buffer size level may be used by the base station to schedulethe one or more DCIs in response to receiving the SR without receivingthe BSR. The wireless device may cancel the BSR in response to theindicated buffer size level via the one or more parameters may be largerthan or equal to a buffer size level computed for the BSR and inresponse to receiving the one or more DCIs.

In an example, the wireless device may cancel the BSR in response to thetransmitting the SR and one or more conditions being met. The one ormore conditions may comprise that the wireless device may provide theone or more parameters for the logical channel to the base station. Theone or more conditions may comprise the indicated buffer size level issufficient to accommodate the new sidelink data.

In an example, the wireless device may further trigger a second SR inresponse to the pending BSR. The wireless device may keep the second SRin response to the receiving the one or more DCIs.

In an example, a wireless device may trigger a sidelink buffer statusreporting (SL BSR) in response to new sidelink data of a logical channelmay arrive to a MAC layer of the wireless device. The wireless devicemay trigger a scheduling request (SR) based on the triggering of the SLBSR. For example, the wireless device may not identify a PUSCH to carrythe SL BSR. For example, if identified, the PUSCH may satisfy a latencyrequirement of the SL BSR and/or the PUSCH is allowed to transmit the SLBSR and/or the BSR may be multiplexed with a data for the PUSCH. Thewireless device may receive from a base station one or more DCIscomprising resource assignments for sidelink transmissions for the newsidelink data. In response to the receiving the one or more DCIs and oneor more criteria being met, the wireless device may cancel the SR. Thewireless device may maintain the pending BSR. The wireless device maycancel the BSR in response to transmitting the BSR or in response tomultiplexing the BSR to a data for a PUSCH or in response to identifyingno pending sidelink data is available for the logical channel or for aSR configuration mapped to the logical channel. The wireless device maytransmit one or more sidelink transport blocks of the new sidelink databased on the one or more DCIs (e.g., sidelink scheduling DCIs).

The one or more criteria may comprise a first case where a priority ofthe logical channel (e.g., the priority of the new sidelink data, thehighest priority of the logical channel, the priority configured by thebase station to the wireless device for the logical channel) is greaterthan or equal to a threshold. The one or more criteria may comprise thata SR configuration (e.g., PUCCH resources or PUCCH resource set for theSR configuration) used for the triggered SR may be configured by thebase station with one or more parameters enabling the cancelling the SRin response to receiving the one or more DCIs comprising resourceassignments for sidelink transmissions. The one or more criteria maycomprise that the logical channel is configured with one or moreparameters enabling the cancelling the SR in response to receiving theone or more DCIs comprising resource assignments for sidelinktransmissions.

In an example, a wireless device may trigger a scheduling request (SR)in response to new sidelink data of a logical channel arrives. Thewireless device may receive from a base station one or more DCIscomprising resource assignments for sidelink transmissions. The wirelessdevice may cancel the SR in response to the receiving the one or moreDCIs. The wireless device may transmit one or more sidelink transportblocks of the new sidelink data based on the one or more DCIs.

In an example, a wireless device may trigger a sidelink buffer statusreporting (SL BSR) in response to new sidelink data of a logical channelmay arrive to a MAC layer of the wireless device. The wireless devicemay trigger a first scheduling request (SR) based on the triggering ofthe SL BSR. For example, the wireless device may not identify a PUSCH tocarry the SL BSR. For example, if identified, the PUSCH may satisfy alatency requirement of the SL BSR and/or the PUSCH is allowed totransmit the SL BSR and/or the BSR may be multiplexed with a data forthe PUSCH. The wireless device may receive from a base station one ormore DCIs comprising resource assignments for sidelink transmissions forthe new sidelink data. The wireless device may cancel the first SR inresponse to the receiving the one or more DCIs. The wireless device maytransmit one or more sidelink transport blocks of the new sidelink databased on the one or more DCIs. The wireless device may determine whetherthe one or more sidelink transport blocks comprise the new sidelinkdata. The wireless device may trigger and transmit a second SR based onthe determining. For example, the wireless device may skiptriggering/transmitting the second SR in response to no new sidelinkdata of the logical channel after transmitting the one or more sidelinktransport blocks is left. For example, the wireless device may transmitthe second SR in response to the remained new sidelink data of thelogical channel after transmitting the one or more sidelink transportblocks. For example, the wireless device may trigger/transmit the secondSR in response to the pending BSR after the transmitting the one or moresidelink transport blocks.

In an example, a wireless device may transmit one or more parameters ofa traffic pattern. For example, the one or more parameters may comprisea traffic type and a logical channel. When the traffic type is aperiodicfor the logical channel, the one or more parameters may comprise a firstbuffer size level. The wireless device may trigger a BSR and compute asecond buffer size level in response to new sidelink data of the logicalchannel being available. The wireless device may transmit a SR for theBSR. The wireless device may receive one or more DCIs comprisingresource assignments for sidelink transmissions for the new sidelinkdata. The wireless device may determine that the first buffer size levelbeing larger than the second buffer size level. Based on thedetermining, the wireless device may cancel the BSR. Otherwise, thewireless device may continue the BSR process. The wireless device maytransmit one or more sidelink transport blocks of the new sidelink databased on the one or more sidelink scheduling DCIs.

According to various embodiments, a device such as, for example, awireless device, off-network wireless device, a base station, and/or thelike, may comprise one or more processors and memory. The memory maystore instructions that, when executed by the one or more processors,cause the device to perform a series of actions. Embodiments of exampleactions are illustrated in the accompanying figures and specification.Features from various embodiments may be combined to create yet furtherembodiments.

FIG. 30 is a flow diagram as per an aspect of an example embodiment ofthe present disclosure. At 3010, a wireless device may transmit one ormore radio resource control (RRC) messages indicating assistanceinformation for a sidelink operation. The assistance information mayindicate an identifier indicating a logical channel associated with asidelink traffic and one or more periodicities associated with thelogical channel. At 3020, in response to the assistance information, awireless device may receive one or more second RRC messages. The one ormore second RRC messages may indicate one or more configured grantconfigurations determined based on the one or more of periodicities ofthe logical channel. At 3030, the wireless device may trigger atransmission of a buffer status report in response to sidelink data ofthe logical channel becoming available. The wireless device may transmita scheduling request (SR). At 3040, in response to the SR, the wirelessdevice may cancel the transmission of the buffer status report and mayreceive one or more activation commands indicating activation of the oneor more configured grant configurations.

According to an example embodiment, the cancelling the transmission ofthe buffer status report may be based on a condition being met. Forexample, the condition may be met when a priority associated with thelogical channel is higher than or equal to a threshold. For example, thecondition may be met when a SR configuration associated with the logicalchannel is configured to skip a buffer status reporting. According to anexample embodiment, the wireless device may receive one or more thirdRRC messages comprising a SR configuration associated with the logicalchannel and a second logical channel. For example, the wireless devicemay trigger a second SR based on data becoming available for the secondlogical channel. For example, the wireless device may cancel the SR inresponse to the receiving the one or more activation commands. Thewireless device may not cancel the second SR in response to thereceiving the one or more activation commands. The wireless device maykeep the second SR in response to the receiving the one or moreactivation commands.

According to an example embodiment, the assistance information furthermay comprise a buffer size level of the logical channel. For example,the buffer size level may indicate a nominal buffer status levelassociated with the logical channel. For example, the cancelling thetransmission of the buffer status report may be in response to the SRand a buffer status level with the sidelink data being equal or smallerthan the buffer size level indicated by the assistance information. Forexample, the wireless device may trigger a second transmission of asecond buffer status report in response to a buffer status level withthe sidelink data being greater than the buffer size level andcancelling the transmission of the buffer status report.

According to an example embodiment, the wireless device may transmit oneor more sidelink transmissions of the sidelink data via one or moresidelink resources of the one or more configured grant configurations.The wireless device may cancel the SR in response to the transmittingthe one or more sidelink transmissions. The wireless device may keep thesecond SR in response to the receiving the one or more activationcommands.

According to an example embodiment, the second logical channel may befor uplink data. According to an example embodiment, the assistanceinformation may further indicate a time offset, a message size, and apriority associated with the logical channel. According to an exampleembodiment, the wireless device may (re)start a SR-retx-tier in responseto the cancelling the SR. The wireless device may retransmit the SR inresponse to an expiry of the SR-retx-timer.

In an example, a wireless device may transmit one or more radio resourcecontrol (RRC) messages indicating assistance information for a sidelinkoperation. For example, the assistant information comprises anidentifier indicating a logical channel associated with a sidelinktraffic and a plurality of periodicities associated with the logicalchannel. In response to the assistance information, the wireless devicemay receive one or more second RRC messages. The one or more RRCmessages may indicate one or more configured grant configurationsdetermined based on the plurality of periodicities of the logicalchannel. The wireless device may trigger a scheduling request based onsidelink data of the logical channel becoming available. The wirelessdevice may receive one or more activation commands indicating activationof the one or more configured grant configurations.

According to an example embodiment, the wireless device may skiptriggering a transmission of a buffer status report in response to thesidelink data of the logical channel becoming available and a conditionbeing met. For example, the condition may be met when a priorityassociated with the logical channel is higher than or equal to athreshold. For example, the condition may be met when the condition ismet when a SR configuration associated with the logical channel isconfigured to skip a buffer status reporting.

In an example, a wireless device may trigger a sidelink buffer statusreport in response to new sidelink data of a logical channel arrives.The wireless device may trigger a scheduling request based on thetriggering of the sidelink buffer status report. The wireless device mayreceive, from a base station, one or more DCIs comprising resourceassignments for sidelink transmissions. The wireless device may cancelthe scheduling request in response to the receiving the one or more DCIsand one or more criteria being met. The wireless device may transmit oneor more sidelink transport blocks of the new sidelink data based on theone or more sidelink scheduling DCIs.

In an example, a wireless device may trigger a sidelink buffer statusreport in response to new sidelink data of a logical channel arrives.The wireless device may trigger a first scheduling request based on thetriggering of the sidelink buffer status report. The wireless device mayreceive, from a base station, one or more DCIs comprising resourceassignments for sidelink transmissions. The wireless device may cancelthe sidelink scheduling request in response to the receiving the one ormore DCIs. The wireless device may transmit one or more sidelinktransport blocks of the new sidelink data based on the one or moresidelink scheduling DCIs. The wireless device may determine whether theone or more sidelink transport blocks comprise the new sidelink data.The wireless device may transmit a second scheduling request based onthe determining.

What is claimed is:
 1. A method comprising: transmitting, by a wirelessdevice, one or more radio resource control (RRC) messages indicatingassistance information for a sidelink operation, wherein the assistanceinformation indicates: an identifier indicating a logical channelassociated with a sidelink traffic; and one or more periodicitiesassociated with the logical channel; receiving, in response to theassistance information, one or more second RRC messages indicating oneor more configured grant configurations determined based on the one ormore of periodicities of the logical channel; triggering, by thewireless device, a transmission of a buffer status report in response tosidelink data of the logical channel becoming available; transmitting ascheduling request (SR); and in response to the SR: cancelling thetransmission of the buffer status report; and receiving one or moreactivation commands indicating activation of the one or more configuredgrant configurations.
 2. The method of claim 1, further comprising thecancelling the transmission of the buffer status report is based on acondition being met.
 3. The method of claim 2, wherein the condition ismet when a priority associated with the logical channel is higher thanor equal to a threshold.
 4. The method of claim 2, wherein the conditionis met when a SR configuration associated with the logical channel isconfigured to skip a buffer status reporting.
 5. The method of claim 1,further comprising receiving one or more third RRC messages comprising aSR configuration associated with the logical channel and a secondlogical channel.
 6. The method of claim 5, further comprising triggeringa second SR based on data becoming available for the second logicalchannel.
 7. The method of claim 6, further comprising cancelling the SRin response to the receiving the one or more activation commands.
 8. Themethod of claim 7, further comprising keeping the second SR in responseto the receiving the one or more activation commands.
 9. The method ofclaim 1, wherein the assistance information further comprises a buffersize level of the logical channel, wherein the buffer size levelindicates a nominal buffer status level associated with the logicalchannel.
 10. The method of claim 9, further comprising the cancellingthe transmission of the buffer status report is in response to the SRand a buffer status level with the sidelink data being equal or smallerthan the buffer size level indicated by the assistance information. 11.A wireless device comprising: one or more processors; and memory storinginstructions that, when executed by the one or more processors, causethe wireless device to: transmit, one or more radio resource control(RRC) messages indicating assistance information for a sidelinkoperation, wherein the assistance information indicates: an identifierindicating a logical channel associated with a sidelink traffic; and oneor more periodicities associated with the logical channel; receive, inresponse to the assistance information, one or more second RRC messagesindicating one or more configured grant configurations determined basedon the one or more of periodicities of the logical channel; trigger, bythe wireless device, a transmission of a buffer status report inresponse to sidelink data of the logical channel becoming available;transmitting a scheduling request (SR); and in response to the SR:cancelling the transmission of the buffer status report; and receivingone or more activation commands indicating activation of the one or moreconfigured grant configurations.
 12. The wireless device of claim 11,wherein the instructions, when executed by the one or more processors,further cause the wireless device to cancel the transmission of thebuffer status report is based on a condition being met.
 13. The wirelessdevice of claim 12, wherein the condition is met when a priorityassociated with the logical channel is higher than or equal to athreshold.
 14. The wireless device of claim 12, wherein the condition ismet when a SR configuration associated with the logical channel isconfigured to skip a buffer status reporting.
 15. The wireless device ofclaim 11, wherein the instructions, when executed by the one or moreprocessors, further cause the wireless device to receive one or morethird RRC messages comprising a SR configuration associated with thelogical channel and a second logical channel.
 16. The wireless device ofclaim 15, wherein the instructions, when executed by the one or moreprocessors, further cause the wireless device to trigger a second SRbased on data becoming available for the second logical channel.
 17. Thewireless device of claim 16, wherein the instructions, when executed bythe one or more processors, further cause the wireless device to cancelthe SR in response to the receiving the one or more activation commands.18. The wireless device of claim 17, wherein the instructions, whenexecuted by the one or more processors, further cause the wirelessdevice to keep the second SR in response to the receiving the one ormore activation commands.
 19. The wireless device of claim 11, whereinthe assistance information further comprises a buffer size level of thelogical channel, wherein the buffer size level indicates a nominalbuffer status level associated with the logical channel.
 20. A systemcomprising: a base station; and a wireless device comprising: one ormore processors; and memory storing instructions that, when executed bythe one or more processors, cause the wireless device to: transmit, tothe base station, one or more radio resource control (RRC) messagesindicating assistance information for a sidelink operation, wherein theassistance information indicates: an identifier indicating a logicalchannel associated with a sidelink traffic; and one or moreperiodicities associated with the logical channel; receive, in responseto the assistance information, one or more second RRC messagesindicating one or more configured grant configurations determined basedon the one or more of periodicities of the logical channel; trigger, bythe wireless device, a transmission of a buffer status report inresponse to sidelink data of the logical channel becoming available;transmitting a scheduling request (SR); and in response to the SR:cancelling the transmission of the buffer status report; and receivingone or more activation commands indicating activation of the one or moreconfigured grant configurations.